1 <!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook V3.1//EN"[
2 <!entity % dummy "IGNORE">
3 <!entity supported SYSTEM "supported.sgml">
4 <!entity newfeatures SYSTEM "newfeatures.sgml">
5 <!entity p-intro SYSTEM "privoxy.sgml">
6 <!entity seealso SYSTEM "seealso.sgml">
7 <!entity contacting SYSTEM "contacting.sgml">
8 <!entity history SYSTEM "history.sgml">
9 <!entity copyright SYSTEM "copyright.sgml">
10 <!entity license SYSTEM "license.sgml">
11 <!entity p-version "3.0.7">
12 <!entity p-status "beta">
13 <!entity % p-not-stable "INCLUDE">
14 <!entity % p-stable "IGNORE">
15 <!entity % p-text "IGNORE"> <!-- define we are not a text only doc -->
16 <!entity % p-doc "INCLUDE"> <!-- and we are a formal doc -->
17 <!entity % p-supp-userman "INCLUDE"> <!-- Include all from supported.sgml -->
18 <!entity my-copy "©"> <!-- kludge for docbook2man -->
19 <!entity % p-newstuff "INCLUDE"> <!-- exclude stuff from devel versions -->
20 <!entity my-app "<application>Privoxy</application>">
23 File : $Source: /cvsroot/ijbswa/current/doc/source/faq.sgml,v $
26 This file belongs into
27 ijbswa.sourceforge.net:/home/groups/i/ij/ijbswa/htdocs/
29 $Id: faq.sgml,v 2.33 2007/11/15 03:30:20 hal9 Exp $
31 Copyright (C) 2001-2007 Privoxy Developers http://privoxy.org
34 Based partially on the Internet Junkbuster FAQ originally written by and
35 Copyright (C) 1997 Anonymous Coders and Junkbusters Corporation.
36 http://www.junkbusters.com/
38 <Qandaset defaultlabel='qanda'>
53 ========================================================================
54 NOTE: Please read developer-manual/documentation.html before touching
57 Please we keep the info in this file as version independent as possible
58 so we only have to maintain one FAQ. Where significant changes are
59 made to Privoxy configuration, please note the change in such a way that
60 it makes sense to both users of older and newer versions.
61 ========================================================================
67 <article id="index" class="faq">
69 <title>Privoxy Frequently Asked Questions</title>
73 <!-- Completely the wrong markup, but very little is allowed -->
74 <!-- in this part of an article. FIXME -->
75 <link linkend="copyright">Copyright</link> &my-copy; 2001-2007 by
76 <ulink url="http://www.privoxy.org/">Privoxy Developers</ulink>
80 <pubdate>$Id: faq.sgml,v 2.33 2007/11/15 03:30:20 hal9 Exp $</pubdate>
84 Note: this should generate a separate page, and a live link to it.
85 But it doesn't for some mysterious reason. Please leave commented
86 unless it can be fixed proper. For the time being, the copyright
87 statement will be in copyright.smgl.
91 <legalnotice id="legalnotice">
93 text goes here ........
103 <orgname>By: Privoxy Developers</orgname>
112 This is here to keep vim syntax file from breaking :/
113 If I knew enough to fix it, I would.
114 PLEASE DO NOT REMOVE! HB: hal@foobox.net
119 This FAQ gives quick answers to frequently asked questions about
120 <ulink url="http://www.privoxy.org/">Privoxy</ulink>.
121 It is not a substitute for the
122 <ulink url="../user-manual/index.html"><citetitle>Privoxy User Manual</citetitle></ulink>.
124 This works, at least in some situtations:
125 Test: <ulink url="privoxy-user-manual.pdf"><citetitle>User Manual</citetitle></ulink>.
129 <!-- Include privoxy.sgml boilerplate: -->
130 <para>What is Privoxy?</para> &p-intro;
131 <!-- end boilerplate -->
134 Please note that this document is a work in progress. This copy represents
135 the state at the release of version &p-version;.
136 You can find the latest version of the document at <ulink
137 url="http://www.privoxy.org/faq/">http://www.privoxy.org/faq/</ulink>.
138 Please see the <link linkend="contact">Contact section</link> if you want to
139 contact the developers.
143 <!-- Feel free to send a note to the developers at <email>ijbswa-developers@lists.sourceforge.net</email>. -->
149 <!-- ~~~~~ New section ~~~~~ -->
151 <sect1 id="general"><title>General Information</title>
152 <sect2 renderas="sect3" id="who-uses"><title>Who should use Privoxy?</title>
154 Anyone that is interested in security, privacy, or in
155 finer-grained control over their web and Internet experience.
156 Everyone is encouraged to try &my-app;.
160 <sect2 renderas="sect3" id="bestchoice"><title>Is Privoxy the best choice for
163 &my-app; is certainly a good choice, especially for those who want more
164 control and security. Those that have the ability to fine-tune their installation
165 will benefit the most. One of <application>Privoxy's</application>
166 strength's is that it is highly configurable giving you the ability to
167 completely personalize your installation. Being familiar with, or at least
168 having an interest in learning about <ulink
169 url="http://en.wikipedia.org/wiki/Http">HTTP</ulink> and other networking
170 protocols, <ulink url="http://en.wikipedia.org/wiki/Html">HTML</ulink>,
171 <ulink url="http://en.wikipedia.org/wiki/Internet_Protocol">IP (Internet
172 Protocol)</ulink>, and
173 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
174 Expressions</quote></ulink>
175 will be a big plus and will help you get the most out of &my-app;.
176 A new installation just includes a very basic configuration. The user
177 should take this as a starting point only, and enhance it as he or she
178 sees fit. In fact, the user is encouraged, and expected to, fine-tune the
182 Much of <application>Privoxy's</application> configuration can be done
183 with a <ulink url="http://en.wikipedia.org/wiki/Web_browser">Web browser</ulink>.
184 But there are areas where configuration is done using a
185 <ulink url="http://en.wikipedia.org/wiki/Text_editors">text editor</ulink>
186 to edit configuration files.
190 <sect2 renderas="sect3" id="proxymoron"><title>What is a <quote>proxy</quote>? How does
191 Privoxy work? </title>
193 A <ulink url="http://en.wikipedia.org/wiki/Proxy_server">web proxy</ulink>
194 is a service, based on a software such as
195 <application>Privoxy</application>, that clients (i.e. browsers) can use
196 instead of connecting directly to web servers on the Internet. The
197 clients then ask the proxy to fetch the objects they need (web pages,
198 images, movies etc) on their behalf, and when the proxy has done so, it
199 hands the results back to the client. It is a <quote>go-between</quote>. See
200 the <ulink url="http://en.wikipedia.org/wiki/Proxy_server">Wikipedia proxy
201 definition</ulink> for more.
204 There are many reasons to use web proxies, such as security (firewalling),
205 efficiency (caching) and others, and there are any number of proxies
206 to accommodate those needs.
209 <application>Privoxy</application> is a proxy that is primarily focused on privacy
210 protection, ad and junk elimination and freeing the user from restrictions placed on his
211 activities. Sitting between your browser(s) and the Internet,
212 it is in a perfect position to filter outbound personal information that your
213 browser is leaking, as well as inbound junk. It uses a variety of techniques to do
214 this, all of which are under your complete control via the various configuration
215 files and options. Being a proxy also makes it easier to share
216 configurations among multiple browsers and/or users.
220 <sect2 renderas="sect3" id="otherstuff">
221 <title>Does Privoxy do anything more than ad blocking?</title>
223 Yes, ad blocking is but one possible use. There are many, many ways &my-app;
224 can be used to sanitize and customize web browsing.
228 <sect2 renderas="sect3" id="newjb"><title>What is this new version of
229 <quote><citetitle>Junkbuster</citetitle></quote>?</title>
231 <!-- Include history.sgml -->
238 <sect2 renderas="sect3">
239 <title id="whyprivoxy">Why <quote>Privoxy</quote>? Why change the name from
240 Junkbuster at all?</title>
242 Though outdated, <ulink url="http://junkbusters.com/">Junkbusters Corporation</ulink>
243 continues to offer their original version of the <application>Internet
244 Junkbuster</application>, so publishing our
245 <application> Junkbuster</application>-derived software under the same name
249 There are also potential legal complications from our use of the
250 <application>Junkbuster</application> name, which is a registered trademark of
251 <ulink url="http://junkbusters.com/">Junkbusters Corporation</ulink>.
252 There are, however, no objections from Junkbusters Corporation to the
253 <application>Privoxy</application> project itself, and they, in fact, still
254 share our ideals and goals.
257 The developers also believed that there are so many improvements over the original
258 code, that it was time to make a clean break from the past and make
259 a name in their own right.
262 <application>Privoxy</application> is the
263 <quote><emphasis>Privacy Enhancing Proxy</emphasis></quote>. Also, its content
264 modification and junk suppression gives <emphasis>you</emphasis>, the user, more
265 control, more freedom, and allows you to browse your personal and
266 <quote><emphasis>private</emphasis> edition</quote> of the web.
270 <sect2 renderas="sect3" id="differs"><title>How does Privoxy differ
271 from the old Junkbuster?</title>
273 <application>Privoxy</application> picks up where
274 <application>Junkbuster</application> left off. All the old features remain.
275 The new <application>Privoxy</application> still blocks ads and banners,
277 url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>, and still
278 helps protect your privacy. But, these have all been greatly enhanced, and many,
279 many new features have been added, all in the same vein.
282 <application>Privoxy</application>'s new features include:
285 <!-- Include newfeatures.sgml: -->
291 <sect2 renderas="sect3" id="whatsanad">
292 <title id="knows">How does Privoxy know what is
293 an ad, and what is not?</title>
295 <application>Privoxy</application>'s approach to blocking ads is twofold:
298 First, there are certain patterns in the <emphasis>locations</emphasis> (URLs)
299 of banner images. This applies to both the path (you wouldn't guess how many
300 web sites serve their banners from a directory called <quote>banners</quote>!)
301 and the host (blocking the big banner hosting services like doublecklick.net
302 already helps a lot). <application>Privoxy</application> takes advantage of this
303 fact by using <ulink url="../user-manual/actions-file.html#AF-PATTERNS">URL
304 patterns</ulink> to sort out and block the requests for things that sound
305 like they would be ads or banners.
308 Second, banners tend to come in certain <emphasis>sizes</emphasis>. But you
309 can't tell the size of an image by its URL without downloading it, and if you
310 do, it's too late to save bandwidth. Therefore, <application>Privoxy</application>
311 also inspects the HTML sources of web pages while they are loaded, and replaces
312 references to images with standard banner sizes by dummy references, so that
313 your browser doesn't request them anymore in the first place.
316 Both of this involves a certain amount of guesswork and is, of course, freely
317 and readily configurable.
321 <sect2 renderas="sect3">
322 <title id="mistakes">Can Privoxy make mistakes?
323 This does not sound very scientific.</title>
325 Actually, it's a black art ;-) And yes, it is always possible to have a broad
326 rule accidentally block or change something by mistake. You will almost surely
327 run into such situations at some point. It is tricky writing rules to
328 cover every conceivable possibility, and not occasionally get false positives.
332 But this should not be a big concern since the
333 <application>Privoxy</application> configuration is very flexible, and
334 includes tools to help identify these types of situations so they can be
335 addressed as needed, allowing you to customize your installation.
336 (<link linkend="badsite">See the Troubleshooting section below</link>.)
341 <sect2 renderas="sect3">
342 <title id="configornot">Will I have to configure Privoxy
343 before I can use it?</title>
345 No, not really. The default installation should give you a good starting
346 point, and block <emphasis>most</emphasis> ads and unwanted content. Many of
347 the more advanced features are off by default, and would require you to
351 You do have to set up your browser to use
352 <application>Privoxy</application> (see the <link
353 linkend="firststep">Installation section below</link>).
356 And you will certainly run into situations where there are false positives,
357 or ads not being blocked that you may not want to see. In these cases, you
358 would certainly benefit by customizing <application>Privoxy's</application>
359 configuration to more closely match your individual situation. And we would
360 encourage you to do this. This is where the real power of
361 <application>Privoxy</application> lies!
366 <sect2 renderas="sect3" id="lan">
367 <title>Can Privoxy run as a server on a network?</title>
369 Yes, &my-app; runs as a server already, and can easily be configured to
370 <quote>serve</quote> more than one client. See <link linkend="lanconfig">
371 How can I set up Privoxy to act as a proxy for my LAN</link> below.
375 <sect2 renderas="sect3" id="browsers2"><title>My browser does the same things as
376 Privoxy. Why should I use Privoxy at all?</title>
378 Modern browsers do indeed have <emphasis>some</emphasis> of the same
379 functionality as <application>Privoxy</application>. Maybe this is
380 adequate for you. But <application>Privoxy</application> is much more
381 versatile and powerful, and can do a number of things that browsers just can't.
384 In addition, a proxy is good choice if you use multiple browsers, or
385 have a LAN with multiple computers since &my-app; can run as a server
386 application. This way all the configuration is in one place, and you don't
387 have to maintain a similar configuration for possibly many browsers or
392 <sect2 renderas="sect3" id="whytrust"><title>Why should I trust Privoxy?</title>
394 The most important reason is because you have access to
395 <emphasis>everything</emphasis>, and you can control everything. You can
396 check every line of every configuration file yourself. You can check every
397 last bit of source code should you desire. And even if you can't read code,
398 there should be some comfort in knowing that <!-- thousands of -->other people can,
399 and do read it. You can build the software from scratch, if you want,
400 so that you know the executable is clean, and that it is
401 <emphasis>yours</emphasis>. In fact, we encourage this level of scrutiny. It
402 is one reason we use &my-app; ourselves.
406 <sect2 renderas="sect3" id="license"><title>Is there is a license or fee? What about a
407 warranty? Registration?</title>
409 <application>Privoxy</application> is licensed under the <ulink
410 url="http://www.gnu.org/licenses/old-licenses/gpl-2.0.html">GNU General Public License (GPL) version 2</ulink>.
411 It is free to use, copy, modify or distribute as you wish under the terms of this
412 license. Please see the <link linkend="copyright">Copyright</link> section for more
413 information on the license and copyright. Or the <filename>LICENSE</filename> file
414 that should be included.
417 There is <emphasis>no warranty</emphasis> of any kind, expressed, implied or otherwise.
418 That is something that would cost real money ;-) There is no registration either.
419 <application>Privoxy</application> really is <emphasis>free</emphasis>
425 <sect2 renderas="sect3" id="spyware">
426 <title>Can Privoxy remove spyware? Adware? Viruses?</title>
428 No, at least not reliably enough to trust it. &my-app; is not designed to be
429 a malware removal tool and the default configuration doesn't even try to
430 filter out any malware.
433 &my-app; could help prevent contact from (known) sites that use such
434 tactics with appropriate configuration rules, and thus could conceivably
435 prevent contamination from such sites.
440 <sect2 renderas="sect3" id="otherads">
441 <title>Can I use Privoxy with other ad-blocking software?</title>
443 &my-app; should work fine with other proxies and other software in general.
446 But it is probably not necessary to use &my-app; in conjunction with other
447 ad-blocking products, and this could conceivably cause undesirable results.
448 It would be better to choose one software or the other and work a little to
449 tweak its configuration to your liking.
453 <sect2 renderas="sect3" id="jointeam"><title>I would like to help you, what can I do?</title>
455 <sect3 renderas="sect4" id="jointeam-work"><title>Would you like to participate?</title>
457 Well, we <emphasis>always</emphasis> need help. There is something for
458 everybody who wants to help us. We welcome new developers, packagers,
459 testers, documentation writers or really anyone with a desire to help in
460 any way. You <emphasis>DO NOT</emphasis> need to be a
461 <quote>programmer</quote>. There are many other tasks available. In fact,
462 the programmers often can't spend as much time programming because of some
463 of the other, more mundane things that need to be done, like checking the
464 Tracker feedback sections.
467 So first thing, <ulink
468 url="https://sourceforge.net/account/register.php">get an account on SourceForge.net</ulink>
469 and mail your id to the <ulink url="mailto:ijbswa-developers@lists.sourceforge.net">developers
470 mailing list</ulink>. Then, please read the <ulink
471 url="../developer-manual/index.html">Developer's Manual</ulink>, at least
472 the pertinent sections.
476 <sect3 renderas="sect4" id="jointeam-money"><title>Contribute!</title>
478 We, of course, welcome donations and could use money for domain registering,
479 buying software to test <application>Privoxy</application> with, and, of course,
480 for regular world-wide get-togethers (hahaha). If you enjoy the software and feel
481 like helping us with a donation, just <ulink
482 url="mailto: ijbswa-developers@lists.sourceforge.net">drop us a note</ulink>.
486 <sect3 renderas="sect4" id="jointeam-software"><title>Software</title>
488 If you are a vendor of a web-related software like a browser, web server
489 or proxy, and would like us to ensure that <application>Privoxy</application>
490 runs smoothly with your product, you might consider supplying us with a
491 copy or license. We can't, however, guarantee that we will fix all potential
492 compatibility issues as a result.
502 <!-- ~~~~~ New section ~~~~~ -->
504 <sect1 id="installation"><title>Installation</title>
506 <sect2 renderas="sect3" id="whichbrowsers">
507 <title>Which browsers are supported by Privoxy?</title>
509 Any browser that can be configured to use a proxy, which
510 should be virtually all browsers, including
511 <application>Firefox</application>, <application>Internet
512 Explorer</application>, <application>Opera</application>, and
513 <application>Safari</application> among others.
514 Direct browser support is not an absolute requirement since
515 <application>Privoxy</application> runs as a separate application and talks
516 to the browser in the standardized HTTP protocol, just like a web server
521 <sect2 renderas="sect3" id="whichos">
522 <title>Which operating systems are supported?</title>
524 Include supported.sgml here:
529 <sect2 renderas="sect3" id="email-client">
530 <title>Can I use Privoxy with my email client?</title>
532 As long as there is some way to set a HTTP proxy for the client, then yes,
533 any application can be used, whether it is strictly speaking a
534 <quote>browser</quote> or not. Though this may not be the best approach for
535 dealing with some of the common abuses of HTML in email. See <link
536 linkend="outlook">How can I configure <application>Privoxy</application>
537 with <application>Outlook Express</application>?</link> below for more on
541 Be aware that HTML email presents a number of unique security and privacy
542 related issues, that can require advanced skills to overcome. The developers
543 recommend using email clients that can be configured to convert HTML to plain
544 text for these reasons.
548 <!-- Nobody is going to still be doing this!
549 <sect2 renderas="sect3" id="newinstall"><title>Can I install
550 Privoxy over Junkbuster?</title>
552 We recommend you un-install <application>Junkbuster</application>
553 first to minimize conflicts and confusion. You may want to
554 save your old configuration files for future reference. The configuration
555 files and syntax have substantially changed, so you will need to manually
556 port your old patterns. See the <ulink url="../user-manual/upgradersnote.html">note
557 to upgraders</ulink> and <ulink url="../user-manual/installation.html">installation
558 chapter</ulink> in the <ulink url="../user-manual/index.html">User Manual</ulink>
562 Note: Some installers may automatically un-install
563 <application>Junkbuster</application>, if present!
569 <sect2 renderas="sect3" id="firststep">
570 <title>I just installed Privoxy. Is there anything
571 special I have to do now?</title>
574 All browsers must be told to use <application>Privoxy</application>
575 as a proxy by specifying the correct proxy address and port number
576 in the appropriate configuration area for the browser. See
577 <ulink url="../user-manual/startup.html">the User Manual for more
578 details</ulink>. You should also flush your browser's memory and disk cache to get rid of any
579 cached junk items, and remove any stored
580 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>.
586 <sect2 renderas="sect3" id="localhost"><title>What is the proxy address of Privoxy?</title>
588 If you set up the <application>Privoxy</application> to run on
589 the computer you browse from (rather than your ISP's server or some
590 networked computer on a LAN), the proxy will be on <literal>127.0.0.1</literal>
591 (sometimes referred to as <quote>localhost</quote>,
592 which is the special name used by every computer on the Internet to refer
593 to itself) and the port will be 8118 (unless you have <application>Privoxy</application>
594 to run on a different port with the <ulink
595 url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink> config option).
598 When configuring your browser's proxy settings you typically enter
599 the word <quote>localhost</quote> or the IP address <quote>127.0.0.1</quote>
600 in the boxes next to <quote>HTTP</quote> and <quote>Secure</quote> (HTTPS) and
601 then the number <quote>8118</quote> for <quote>port</quote>.
602 This tells your browser to send all web requests to <application>Privoxy</application>
603 instead of directly to the Internet.
606 <application>Privoxy</application> can also be used to proxy for
607 a Local Area Network. In this case, your would enter either the IP
608 address of the LAN host where <application>Privoxy</application>
609 is running, or the equivalent hostname, e.g. <literal>192.168.1.1</literal>.
610 Port assignment would be same as above. Note that
611 <application>Privoxy</application> doesn't listen on any LAN interfaces by
615 <application>Privoxy</application> does not currently handle
616 any other protocols such as FTP, SMTP, IM, IRC, ICQ, etc. Be sure that
617 proxying any of these other protocols is not activated.
621 <sect2 renderas="sect3" id="nothing">
622 <title>I just installed Privoxy, and nothing is happening.
623 All the ads are there. What's wrong?</title>
626 Did you configure your browser to use <application>Privoxy</application>
627 as a proxy? It does not sound like it. See above. You might also try flushing
628 the browser's caches to force a full re-reading of pages. You can verify
629 that <application>Privoxy</application> is running, and your browser
630 is correctly configured by entering the special URL:
631 <ulink url="http://p.p/">http://p.p/</ulink>.
632 <!-- Use http://p.p/ instead of http://config.privoxy.org/ here because
633 of potential redirect caching problem (see next Q). -->
634 This should take you to a page titled <quote>This is Privoxy..</quote> with
635 access to <application>Privoxy's</application> internal configuration.
636 If you see this, then you are good to go. If you receive a page saying
637 <quote>Privoxy is not running</quote>, then the browser is not set up to use
638 your <application>Privoxy</application> installation.
639 If you receive anything else (probably nothing at all), it could either
640 be that the browser is not set up correctly, or that
641 <application>Privoxy</application> is not running at all. Check the <ulink
642 url="../user-manual/config.html#LOGFILE">log file</ulink>. For instructions
643 on starting <application>Privoxy</application> and browser configuration,
644 see the <ulink url="http://www.privoxy.org/user-manual/startup.html">chapter
645 on starting <application>Privoxy</application></ulink> in the
646 <ulink url="http://www.privoxy.org/user-manual/">User Manual</ulink>.
651 <sect2 renderas="sect3" id="notused">
652 <title>I get a <quote>Privoxy is not being used</quote> dummy page although
653 Privoxy is running and being used.</title>
656 First, make sure that Privoxy is <emphasis>really</emphasis> running and
657 being used by visiting <ulink url="http://p.p/">http://p.p/</ulink>. You
658 should see the <application>Privoxy</application> main page. If not, see
659 the <ulink url="http://www.privoxy.org/user-manual/startup.html">chapter
660 on starting <application>Privoxy</application></ulink> in the
661 <ulink url="http://www.privoxy.org/user-manual/">User Manual</ulink>.
665 Now if <ulink url="http://p.p/">http://p.p/</ulink> works for you, but
666 other parts of <application>Privoxy</application>'s web interface show
667 the dummy page, your browser has cached a redirection it encountered before
668 <application>Privoxy</application> was being used. You need to clear your
669 browser's cache. Note that shift-reloading the dummy page won't help, since
670 that'll only refresh the dummy page, not the redirection that lead you there.
674 The procedure for clearing the cache varies from browser to browser. For
675 example, <application>Mozilla/Netscape</application> users would click
676 <guibutton>Edit</guibutton> --> <guibutton>Preferences</guibutton> -->
677 <guibutton>Advanced</guibutton> --> <guibutton>Cache</guibutton> and
678 then click both <quote><guibutton>Clear Memory Cache</guibutton></quote>
679 and <quote><guibutton>Clear Disk Cache</guibutton></quote>.
680 And, <application>Firefox</application> users would click
681 <guibutton>Tools</guibutton> --> <guibutton>Options</guibutton> -->
682 <guibutton>Privacy</guibutton> --> <guibutton>Cache</guibutton> and
683 then click <quote><guibutton>Clear Cache Now</guibutton></quote>.
691 <!-- ~~~~~ New section ~~~~~ -->
693 <sect1 id="configuration"><title>Configuration</title>
694 <sect2 renderas="sect3">
695 <title id="actionsfile">What exactly is an <quote>actions</quote> file?</title>
698 &my-app; utilizes the concept of <quote>
699 <ulink url="../user-manual/actions-file.html#ACTIONS">actions</ulink></quote>
700 that are used to manipulate and control web page data.
701 <ulink url="../user-manual/actions-file.html">Actions files</ulink>
702 are where these <ulink url="../user-manual/actions-file.html#ACTIONS">actions</ulink>
703 that <application>Privoxy</application> could take while processing a certain
704 request, are configured. Typically, you would define a set of default actions
705 that apply globally to all URLs, then add exceptions to these defaults where needed.
706 There is a wide array of actions available that give the user a high degree
707 of control and flexibility on how to process each and every web page.
711 Actions can be defined on a <ulink
712 url="../user-manual/actions-file.html#AF-PATTERNS">URL pattern</ulink> basis, i.e.
713 for single URLs, whole web sites, groups or parts thereof etc. Actions can also be
714 grouped together and then applied to requests matching one or more patterns.
715 There are many possible actions that might apply to any given site. As an example,
716 if you are blocking <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>
717 as one of your default actions, but need to accept cookies from a given site,
718 you would need to define an exception for this site in one of your actions
719 files, preferably in <filename>user.action</filename>.
724 <sect2 renderas="sect3" id="actionss">
725 <title>The <quote>actions</quote> concept confuses me. Please list
726 some of these <quote>actions</quote>.</title>
728 For a comprehensive discussion of the actions concept, please refer
729 to the <ulink url="../user-manual/actions-file.html">actions file
730 chapter</ulink> in the <ulink url="../user-manual/index.html">User
731 Manual</ulink>. It includes a <ulink
732 url="../user-manual/actions-file.html#ACTIONS">list of all actions</ulink>
733 and an <ulink url="../user-manual/actions-file.html#ACT-EXAMPLES">actions
734 file tutorial</ulink> to get you started.
739 <sect2 renderas="sect3">
740 <title id="actconfig">How are actions files configured? What is the easiest
741 way to do this?</title>
744 Actions files are just text files in a special syntax and can be edited
745 with a text editor. But probably the easiest way is to access
746 <application>Privoxy</application>'s user interface with your web browser
747 at <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
748 (Shortcut: <ulink url="http://p.p/">http://p.p/</ulink>) and then select
749 <quote><ulink url="http://config.privoxy.org/show-status">View &
750 change the current configuration</ulink></quote> from the menu. Note
751 that this feature must be explicitly enabled in the main config file
753 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>).
758 <sect2 renderas="sect3">
759 <title>There are several different <quote>actions</quote> files. What are
760 the differences?</title>
763 are being included by the developers, to be used for
764 different purposes: These are
765 <filename>default.action</filename>, the <quote>main</quote> actions file
766 which is actively maintained by the <application>Privoxy</application>
767 developers and typically sets the default policies, <filename>user.action</filename>, where users are encouraged
768 to make their private customizations, and <filename>standard.action</filename>,
769 which is for internal <application>Privoxy</application> use only.
770 Please see <ulink url="../user-manual/actions-file.html">the actions chapter</ulink>
771 in the <ulink url="../user-manual/index.html">User Manual</ulink> for a more
772 detailed explanation.
776 Earlier versions included three different versions of the
777 <filename>default.action</filename> file. The new scheme allows for
778 greater flexibility of local configuration, and for browser based
779 selection of pre-defined <quote>aggressiveness</quote> levels.
784 <sect2 renderas="sect3" id="getupdates"><title>Where can I get updated Actions Files?</title>
786 Based on your feedback and the continuing development, updates of
787 <filename>default.action</filename> will be
788 made available from time to time on the <ulink
789 url="http://sourceforge.net/project/showfiles.php?group_id=11118">files section</ulink> of
790 our <ulink url="http://sf.net/projects/ijbswa/">project page</ulink>.
794 If you wish to receive an email notification whenever we release updates of
795 <application>Privoxy</application> or the actions file, <ulink
796 url="http://lists.sourceforge.net/lists/listinfo/ijbswa-announce/">subscribe
797 to our announce mailing list</ulink>, ijbswa-announce@lists.sourceforge.net.
802 <sect2 renderas="sect3" id="newconfig"><title>Can I use my old config files?</title>
804 The syntax and purpose of configuration files has remained roughly the
805 same throughout the 3.x series, but backwards compatibility is not guaranteed.
806 Also each release contains updated, <quote>improved</quote> versions and it is
807 therefore strongly recommended to use the newer configuration files.
811 <sect2 renderas="sect3" id="difficult">
812 <title>Why is the configuration so complicated?</title>
814 <quote>Complicated</quote> is in the eye of the beholder. Those that are
815 familiar with some of the underlying concepts, such as regular expression
816 syntax, take to it like a fish takes to water. Also, software that tries
817 hard to be <quote>user friendly</quote>, often lacks sophistication and
818 flexibility. There is always that trade-off there between power vs.
819 easy-of-use. Furthermore, anyone is welcome to contribute ideas and
820 implementations to enhance &my-app;.
824 <sect2 renderas="sect3" id="yahoo"><title>How can I make my Yahoo/Hotmail/Gmail account work?</title>
826 The default configuration shouldn't impact the usability of any of these services.
827 It may, however, make all <ulink
828 url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>
829 temporary, so that your browser will forget your
830 login credentials in between browser sessions. If you would like not to have to log
831 in manually each time you access those websites, simply turn off all cookie handling
832 for them in the <filename>user.action</filename> file. An example for yahoo might
836 <screen># Allow all cookies for Yahoo login:
838 { -<ulink url="../user-manual/actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</ulink> -<ulink url="../user-manual/actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</ulink> -<ulink url="../user-manual/actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</ulink> }
839 .login.yahoo.com</screen>
842 These kinds of sites are often quite complex and heavy with
843 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink> and
844 thus <quote>fragile</quote>. So if <emphasis>still</emphasis> a problem,
846 url="../user-manual/actions-file.html#ALIASES">alias</ulink> just for such
850 <screen># Gmail is a _fragile_ site:
852 { <literal>fragile</literal> }
854 mail.google.com</screen>
857 Be sure to flush your browser's caches whenever making these kinds of
858 changes, just to make sure the changes <quote>take</quote>.
861 Make sure the domain, host and path are appropriate as well. Your browser can
862 tell you where you are specifically and you should use that information for
863 your configuration settings. Note that above it is not referenced as
864 <literal>gmail.com</literal>, which is a valid domain name.
869 <sect2 renderas="sect3" id="configfiles"> <title>What's the difference between the
870 <quote>Cautious</quote>, <quote>Medium</quote> and <quote>Advanced</quote> defaults?</title>
872 Configuring <application>Privoxy</application> is not entirely trivial. To
873 help you get started, we provide you with three different default action
874 <quote>profiles</quote> in the web based actions file editor at <ulink
875 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>.
876 See the <ulink url="../user-manual/actions-file.html"><citetitle>User
877 Manual</citetitle></ulink> for a list of actions, and how the default
882 Where the defaults are likely to break some sites, exceptions for
883 known popular <quote>problem</quote> sites are included, but in
884 general, the more aggressive your default settings are, the more exceptions
885 you will have to make later. New users are best to start off in
886 <quote>Cautious</quote> setting. This is safest and will have the fewest
887 problems. See the <ulink
888 url="../user-manual/index.html"><citetitle>User Manual</citetitle></ulink>
889 for a more detailed discussion.
893 It should be noted that the <quote>Advanced</quote> profile (formerly known
894 as the <quote>Adventuresome</quote> profile) is more
895 aggressive, and will make use of some of
896 <application>Privoxy's</application> advanced features. Use at your own risk!
901 <sect2 renderas="sect3" id="browseconfig"> <title>Why can I change the configuration
902 with a browser? Does that not raise security issues?</title>
904 It may seem strange that regular users can edit the config files with their
905 browsers, although the whole <filename>/etc/privoxy</filename> hierarchy
906 belongs to the user <quote>privoxy</quote>, with only 644 permissions.
909 When you use the browser-based editor, <application>Privoxy</application>
910 itself is writing to the config files. Because
911 <application>Privoxy</application> is running as the user <quote>privoxy</quote>,
912 it can update its own config files.
915 If you run <application>Privoxy</application> for multiple untrusted users (e.g. in
916 a LAN), you will probably want to make sure that the the web-based
917 editor and remote toggle features are <quote>off</quote> by setting <quote><literal><ulink
918 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>
919 0</literal></quote> and <quote><literal><ulink
920 url="../user-manual/config.html#ENABLE-REMOTE-TOGGLE">enable-remote-toggle</ulink>
921 0</literal></quote> in the <ulink url="../user-manual/config.html">main configuration file</ulink>.
924 Note that in the default configuration, only local users (i.e. those on
925 <quote>localhost</quote>) can connect to <application>Privoxy</application>,
926 so this is (normally) not a security problem.
931 <sect2 renderas="sect3">
932 <title id="filterfile">What is the <filename>default.filter</filename> file? What is a <quote>filter</quote>?</title>
934 The <ulink url="../user-manual/filter-file.html"><filename>default.filter</filename></ulink>
935 file is where <emphasis>filters</emphasis> as supplied by the developers are defined.
936 Filters are a special subset of actions that can be used to modify or
937 remove, web page content on the fly. Filters apply to <emphasis>anything</emphasis>
938 in the page source (and optionally both client and server headers), including
939 HTML tags, and JavaScript. Regular expressions are used to accomplish this.
940 There are a number of pre-defined filters to deal with common annoyances. The
941 filters are only defined here, to invoke them, you need to use the
943 url="../user-manual/actions-file.html#FILTER"><literal>filter</literal>
944 action</ulink> in one of the actions files. Filtering is automatically
945 disabled for inappropriate MIME types. Filters should
946 <emphasis>not</emphasis> be confused with <ulink
947 url="../user-manual/actions-file.html#BLOCK"><literal>blocks</literal></ulink>, which
948 is a completely different action, and is more typically used to block ads and
953 If you are familiar with regular expressions, and HTML, you can look at
954 the provided <filename>default.filter</filename> with a text editor and define
955 your own filters. This is potentially a very powerful feature, but
956 requires some expertise in both regular expressions and HTML/HTTP.
957 <![%p-newstuff;[ You should
958 place any modifications to the default filters, or any new ones you create
959 in a separate file, such as <filename>user.filter</filename>, so they won't
960 be overwritten during upgrades.
961 The ability to define multiple filter files
962 in <filename>config</filename> is a new feature as of v. 3.0.5.]]>
966 There is no GUI editor option for this part of the configuration,
967 but you can disable/enable the various pre-defined filters of the included
968 <filename>default.filter</filename> file with the <ulink
969 url="http://config.privoxy.org/show-status">web-based actions file editor</ulink>
971 that the custom actions editor must be explicitly enabled in the main config file
973 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>).
979 <sect2 renderas="sect3" id="lanconfig">
980 <title>How can I set up Privoxy to act as a proxy for my
983 By default, <application>Privoxy</application> only responds to requests
984 from <literal>127.0.0.1</literal> (localhost). To have it act as a server for
985 a network, this needs to be changed in the <ulink
986 url="../user-manual/config.html">main configuration file</ulink>. Look for
988 url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink></literal>
989 option, which may be commented out with a <quote>#</quote> symbol. Make sure
990 it is uncommented, and assign it the address of the LAN gateway interface,
991 and port number to use. Assuming your LAN address is 192.168.1.1 and you
992 wish to run <application>Privoxy</application> on port 8118, this line
998 listen-address 192.168.1.1:8118</screen>
1002 Save the file, and restart <application>Privoxy</application>. Configure
1003 all browsers on the network then to use this address and port number.
1007 Alternately, you can have <application>Privoxy</application> listen on
1008 all available interfaces:
1013 listen-address :8118</screen>
1017 And then use <application>Privoxy's</application>
1019 url="../user-manual/config.html#PERMIT-ACCESS">permit-access</ulink>
1020 feature to limit connections. A firewall in this situation is recommended
1025 The above steps should be the same for any TCP network, regardless of
1030 If you run <application>Privoxy</application> on a LAN with untrusted users,
1031 we recommend that you double-check the <ulink
1032 url="../user-manual/config.html#ACCESS-CONTROL">access control and security</ulink>
1039 <sect2 renderas="sect3">
1040 <title id="noseeum">Instead of ads, now I get a checkerboard pattern. I don't want to see anything.</title>
1042 The replacement for blocked images can be controlled with the <ulink
1043 url="../user-manual/actions-file.html#SET-IMAGE-BLOCKER"><literal>set-image-blocker</literal>
1044 action</ulink>. You have the choice of a checkerboard pattern, a transparent 1x1 GIF
1045 image (aka <quote>blank</quote>), or a redirect to a custom image of your choice.
1046 Note that this choice only has effect for images which are blocked as images, i.e.
1047 whose URLs match both a <literal><ulink
1048 url="../user-manual/actions-file.html#HANDLE-AS-IMAGE">handle-as-image</ulink></literal>
1049 <emphasis>and</emphasis> <literal><ulink
1050 url="../user-manual/actions-file.html#BLOCK">block</ulink></literal> action.
1053 If you want to see nothing, then change the <ulink
1054 url="../user-manual/actions-file.html#SET-IMAGE-BLOCKER"><literal>set-image-blocker</literal>
1055 action</ulink> to <quote>blank</quote>. This can be done by editing the
1056 <filename>user.action</filename> file, or through the <ulink
1057 url="http://config.privoxy.org/show-status">web-based actions file editor</ulink>.
1062 <sect2 renderas="sect3">
1063 <title id="whyseeum">Why would anybody want to see a checkerboard pattern?</title>
1065 Remember that <link linkend="whatsanad">telling which image is an ad and which
1066 isn't</link>, is an educated guess. While we hope that the standard configuration
1067 is rather smart, it will make occasional mistakes. The checkerboard image is visually
1068 decent, and it shows you where images have been blocked, which can be very
1069 helpful in case some navigation aid or otherwise innocent image was
1070 erroneously blocked. It is recommended for new users so they can
1071 <quote>see</quote> what is happening. Some people might also enjoy seeing how
1072 many banners they <emphasis>don't</emphasis> have to see.
1077 <sect2 renderas="sect3">
1078 <title id="blockedbytext">I see some images being replaced with text
1079 instead of the checkerboard image. Why and how do I get rid of this?</title>
1081 This happens when the banners are not embedded in the HTML code of the
1082 page itself, but in separate HTML (sub)documents that are loaded into (i)frames
1083 or (i)layers, and these external HTML documents are blocked. Being non-images
1084 they get replaced by a substitute HTML page rather than a substitute image,
1085 which wouldn't work out technically, since the browser expects and accepts
1086 only HTML when it has requested an HTML document.
1089 The substitute page adapts to the available space and shows itself as a
1090 miniature two-liner if loaded into small frames, or full-blown with a
1091 large red "BLOCKED" banner if space allows.
1094 If you prefer the banners to be blocked by images, you must see to it that
1095 the HTML documents in which they are embedded are not blocked. Clicking
1096 the <quote>See why</quote> link offered in the substitute page will show
1097 you which rule blocked the page. After changing the rule and un-blocking
1098 the HTML documents, the browser will try to load the actual banner images
1099 and the usual image blocking will (hopefully!) kick in.
1104 <sect2 renderas="sect3" id="srvany">
1105 <title>Can Privoxy run as a service
1106 on Win2K/NT/XP?</title>
1109 Yes. Version 3.0.5 introduces full <application>Windows</application> service
1110 functionality. See <ulink url="../user-manual/installation.html#installation-pack-win">
1111 the <citetitle>User Manual</citetitle></ulink> for details on how to install and configure
1112 <application>Privoxy</application> as a service.
1115 Earlier ]]>3.x versions could run as a system service using <command>srvany.exe</command>.
1116 See the discussion at <ulink
1117 url="http://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118">http://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118</ulink>,
1118 for details, and a sample configuration.
1123 <sect2 renderas="sect3" id="otherproxy">
1124 <title>How can I make Privoxy work with other
1125 proxies like Squid or Tor?</title>
1127 This can be done and is often useful to combine the benefits of
1128 <application>Privoxy</application> with those of a another proxy.
1130 url="../user-manual/config.html#FORWARDING">forwarding chapter</ulink>
1131 in the <ulink url="../user-manual/index.html">User Manual</ulink> which
1132 describes how to do this, and the <link linkend="TOR">
1133 How do I use Privoxy together with
1134 Tor</link> section below.
1138 <sect2 renderas="sect3" id="port-80">
1139 <title>Can I just set Privoxy to use port 80
1140 and thus avoid individual browser configuration?</title>
1143 No, its more complicated than that. This only works with special kinds
1144 of proxies known as <quote>intercepting</quote> proxies (see below).
1149 <sect2 renderas="sect3" id="transparent">
1150 <title>Can Privoxy run as a <quote>transparent
1151 </quote> proxy?</title>
1153 The whole idea of Privoxy is to modify client requests
1154 and server responses in all sorts of ways and therefore
1155 it's not a transparent proxy as described in
1156 <ulink url="http://tools.ietf.org/html/rfc2616">RFC 2616</ulink>.
1159 However, some people say <quote>transparent proxy</quote> when they
1160 mean <quote>intercepting proxy</quote>. If you are one of them,
1161 please read the <ulink url="#intercepting">next entry</ulink>.
1166 <sect2 renderas="sect3" id="intercepting">
1167 <title>Can Privoxy run as a <quote>intercepting</quote> proxy?</title>
1169 <application>Privoxy</application> can't intercept traffic itself,
1170 but it can handle requests that where intercepted and redirected
1171 with a packet filter (like <application>PF</application> or
1172 <application>iptables</application>), as long as the <literal>Host</literal>
1176 As the <literal>Host</literal> header is required by HTTP/1.1 and as most
1177 web sites don't work if it isn't set, this limitation shouldn't be a
1181 Please refer to your packet filter's documentation to learn how to
1182 intercept and redirect traffic into <application>Privoxy</application>. Afterward you just have
1183 to configure <application>Privoxy</application> to
1184 <ulink url="../user-manual/config.html#ACCEPT-INTERCEPTED-REQUESTS">accept intercepted requests</ulink>.
1189 <sect2 renderas="sect3" id="outlook">
1190 <title>How can I configure Privoxy for use with Outlook
1193 <application>Outlook Express</application> uses <application>Internet Explorer</application>
1194 components to both render HTML, and fetch any HTTP requests that may be embedded in an HTML email.
1195 So however you have <application>Privoxy</application> configured to work
1196 with IE, this configuration should automatically be shared.
1200 <sect2 renderas="sect3" id="outlook-more">
1201 <title>How can I have separate rules just for HTML mail?</title>
1203 The short answer is, you can't. <application>Privoxy</application> has no way
1204 of knowing which particular application makes a request, so there is no way to
1205 distinguish between web pages and HTML mail.
1206 <application>Privoxy</application> just blindly proxies all requests. In the
1207 case of <application>Outlook Express</application> (see above), OE uses
1208 IE anyway, and there is no way for <application>Privoxy</application> to ever
1209 be able to distinguish between them (nor could any other proxy type application for
1213 For a good discussion of some of the issues involved (including privacy and
1214 security issues), see
1215 <ulink url="http://sourceforge.net/tracker/?func=detail&atid=211118&aid=629518&group_id=11118">http://sourceforge.net/tracker/?func=detail&atid=211118&aid=629518&group_id=11118</ulink>.
1219 <sect2 renderas="sect3" id="sneaky-cookies">
1220 <title>I sometimes notice cookies sneaking through. How?</title>
1223 url="http://en.wikipedia.org/wiki/Browser_cookie">Cookies</ulink> can be
1224 set in several ways. The classic method is via the
1225 <literal>Set-Cookie</literal> HTTP header. This is straightforward, and an
1226 easy one to manipulate, such as the &my-app; concept of
1227 <ulink url="../user-manual/actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</ulink>.
1228 There is also the possibility of using
1229 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink> to
1230 set cookies (&my-app; calls these <literal>content-cookies</literal>). This
1231 is trickier because the syntax can vary widely, and thus requires a certain
1232 amount of guesswork. It is not realistic to catch all of these short of
1233 disabling Javascript, which would break many sites. And lastly, if the
1234 cookies are embedded in a HTTPS/SSL secure session via Javascript, they are beyond
1235 <application>Privoxy's</application> reach.
1238 All in all, &my-app; can help manage cookies in general, can help minimize
1239 the loss of privacy posed by cookies, but can't realistically stop all
1244 <sect2 renderas="sect3" id="evil-cookies">
1245 <title>Are all cookies bad? Why?</title>
1247 No, in fact there are many beneficial uses of
1249 url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>. Cookies are just a
1250 method that browsers can use to store data between pages, or between browser
1251 sessions. Sometimes there is a good reason for this, and the user's life is a
1252 bit easier as a result. But there is a long history of some websites taking
1253 advantage of this layer of trust, and using the data they glean from you and
1254 your browsing habits for their own purposes, and maybe to your potential
1255 detriment. Such sites are using you and storing their data on your system.
1256 That is why the privacy conscious watch from whom those cookies come, and why
1257 they really <emphasis>need</emphasis> to be there.
1261 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">Wikipedia cookie
1262 definition</ulink> for more.
1266 <sect2 renderas="sect3" id="allow-cookies">
1267 <title>How can I allow permanent cookies for my trusted sites?</title>
1270 There are several actions that relate to cookies. The default behavior is to
1271 allow only <quote>session cookies</quote>, which means the cookies only last
1272 for the current browser session. This eliminates most kinds of abuse related
1273 to cookies. But there may be cases where you want cookies to last.
1276 To disable all cookie actions, so that cookies are allowed unrestricted,
1277 both in and out, for <literal>example.com</literal>:
1281 { -crunch-incoming-cookies -crunch-outgoing-cookies -session-cookies-only -filter{content-cookies} }
1282 .example.com</screen>
1285 Place the above in <filename>user.action</filename>. Note that some of these may
1286 be off by default anyway, so this might be redundant, but there is no harm
1287 being explicit in what you want to happen. <filename>user.action</filename>
1288 includes an alias for this situation, called
1289 <literal>allow-all-cookies</literal>.
1293 <sect2 renderas="sect3" id="multiples">
1294 <title>Can I have separate configurations for different users?</title>
1296 Each instance of <application>Privoxy</application> has its own
1297 configuration, including such attributes as the TCP port that it listens on.
1298 What you can do is run multiple instances of <application>Privoxy</application>, each with
1300 <ulink url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink>
1301 configuration setting, and configuration path, and then
1302 each of these can have their own configurations. Think of it as per-port
1306 Simple enough for a few users, but for large installations, consider having
1307 groups of users that might share like configurations.
1311 <sect2 renderas="sect3" id="whitelists">
1312 <title>Can I set-up Privoxy as a whitelist of
1313 <quote>good</quote> sites?</title>
1315 Sure. There are a couple of things you can do for simple white-listing.
1316 Here's one real easy one:
1319 ############################################################
1321 ############################################################
1322 { <ulink url="../user-manual/actions-file.html#BLOCK">+block</ulink> }
1323 / # Block *all* URLs
1325 ############################################################
1327 ############################################################
1328 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> }
1331 games.example.com</screen>
1333 This allows access to only those three sites by first blocking all URLs, and
1334 then subsequently allowing three specific exceptions.
1337 A more interesting approach is <application>Privoxy's</application>
1338 <literal>trustfile</literal> concept, which incorporates the notion of
1339 <quote>trusted referrers</quote>. See the <ulink
1340 url="../user-manual/config.html#TRUSTFILE">User Manual Trust</ulink>
1344 These are fairly simple approaches and are not completely foolproof. There
1345 are various other configuration options that should be disabled (described
1346 elsewhere here and in <ulink url="../user-manual/">the User Manual</ulink>)
1347 so that users can't modify their own configuration and easily circumvent the
1352 <sect2 renderas="sect3" id="no-adblock">
1353 <title>How can I turn off ad-blocking?</title>
1355 Ad blocking is achieved through a complex application of various &my-app;
1356 <ulink url="../user-manual/actions-file.html">actions</ulink>. These
1357 actions are deployed against simple images, banners, flash animations,
1358 text pages, JavaScript, pop-ups and pop-unders, etc., so its not as simple as
1359 just turning one or two actions off. The various actions that make up
1360 &my-app; ad blocking are hard-coded into the default configuration files. It
1361 has been assumed that everyone using &my-app; is interested in this
1365 If you want to do without this, there are several approaches you can take:
1366 You can manually undo the many block rules in
1367 <filename>default.action</filename>. Or even easier, just create your own
1368 <filename>default.action</filename> file from scratch without the many ad
1369 blocking rules, and corresponding exceptions. Or lastly, if you are not
1370 concerned about the additional blocks that are done for privacy reasons, you
1371 can very easily over-ride <emphasis>all</emphasis> blocking with the
1372 following very simple rule in your <filename>user.action</filename>:
1376 # Unblock everybody, everywhere
1377 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> }
1378 / # UN-Block *all* URLs</screen>
1381 Or even a more comprehensive reversing of various ad related actions:
1385 # Unblock everybody, everywhere, and turn off appropriate filtering, etc
1386 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> \
1387 <ulink url="../user-manual/actions-file.html#FILTER-BANNERS-BY-SIZE">-filter{banners-by-size}</ulink> \
1388 <ulink url="../user-manual/actions-file.html#FILTER-BANNERS-BY-LINK">-filter{banners-by-link}</ulink> \
1389 <literal>allow-popups</literal> \
1391 / # UN-Block *all* URLs and allow ads</screen>
1394 This last <quote>action</quote> in this compound statement,
1395 <literal>allow-popups</literal>, is an <ulink
1396 url="../user-manual/actions-file.html#ALIASES">alias</ulink> that disables
1397 various pop-up blocking features.
1401 <sect2 renderas="sect3" id="templates">
1402 <title>How can I have custom template pages, like the
1403 <emphasis>BLOCKED</emphasis> page?</title>
1405 &my-app; <quote>templates</quote> are specialized text files utilized by
1406 &my-app; for various purposes and can easily be modified using any text
1407 editor. All the template pages are installed in a sub-directory appropriately
1408 named: <filename>templates</filename>. Knowing something about HTML syntax
1409 will of course be helpful. Be forewarned that the default templates are
1410 subject to being overwritten during upgrades. You can, however, create
1411 completely new templates by specifying an alternate path for them in the main
1412 <filename>config</filename>, see the <ulink
1413 url="../user-manual/config.html#templdir">templdir</ulink> option.
1417 <sect2 renderas="sect3" id="blockall">
1418 <title>How can I remove the <quote>Go There Anyway</quote> link from
1419 the <emphasis>BLOCKED</emphasis> page?</title>
1421 There is more than one way to do it.
1424 Editing the BLOCKED template page (see above) may dissuade some users, but
1425 this method is easily circumvented. Where you need this level of control, you
1426 should build &my-app; from source, and enable various features that are
1427 available as compile-time options. You should
1428 <command>configure</command> the sources as follows:
1432 ./configure --disable-toggle --disable-editor --disable-force</screen>
1435 This will create an executable with hard-coded security features so that
1436 &my-app; does not allow easy bypassing of blocked sites, or changing the
1437 current configuration via any connected user's web browser.
1440 Note that all of these features can also be toggled on/off via options in
1441 <application>Privoxy's</application> main <ulink
1442 url="../user-manual/config.html#ACCESS-CONTROL">config</ulink> file which
1443 means you don't have to recompile anything.
1449 <!-- ~ End section ~ -->
1452 <!-- ~~~~~ New section ~~~~~ -->
1454 <sect1 id="misc"><title>Miscellaneous</title>
1456 <sect2 renderas="sect3">
1457 <title id="slowsme">How much does Privoxy slow my browsing down? This
1458 has to add extra time to browsing.</title>
1460 How much of an impact depends on many things, including the CPU of the host
1461 system, how aggressive the configuration is, which specific actions are being triggered,
1462 the size of the page, the bandwidth of the connection, etc.
1465 Overall, it should not slow you down any in real terms, and may actually help
1466 speed things up since ads, banners and other junk are not typically being
1467 retrieved and displayed. The actual processing time required by
1468 <application>Privoxy</application> itself for each page, is relatively small
1469 in the overall scheme of things, and happens very quickly. This is typically
1470 more than offset by time saved not downloading and rendering ad images and
1471 other junk content (if ad blocking is being used).
1475 <quote>Filtering</quote> content via the <literal><ulink
1476 url="../user-manual/actions-file.html#FILTER">filter</ulink></literal> or
1478 url="../user-manual/actions-file.html#DEANIMATE-GIFS">deanimate-gifs</ulink></literal>
1479 actions may cause a perceived slowdown, since the entire document
1480 needs to be buffered before displaying. And on very large documents, filtering may have
1481 some measurable impact. How much depends on the page size, the actual
1482 definition of the filter(s), etc. See below. Most other actions have little
1483 to no impact on speed.
1486 Also, when filtering is enabled but zlib support isn't available, compression
1487 is often disabled (see <ulink
1488 url="../user-manual/actions-file.html#PREVENT-COMPRESSION">prevent-compression</ulink>).
1489 This can have an impact on speed as well. Again, the page size, etc. will
1490 determine how much of an impact.
1496 <sect2 renderas="sect3" id="loadingtimes"><title>I notice considerable
1497 delays in page requests. What's wrong?</title>
1499 If you use any <literal><ulink
1500 url="../user-manual/actions-file.html#FILTER">filter</ulink></literal> action,
1501 such as filtering banners by size, web-bugs etc, or the <literal><ulink
1502 url="../user-manual/actions-file.html#DEANIMATE-GIFS">deanimate-gifs</ulink></literal>
1503 action, the entire document must be loaded into memory in order for the filtering
1504 mechanism to work, and nothing is sent to the browser during this time.
1507 The loading time typically does not really change much in real numbers, but
1508 the feeling is different, because most browsers are able to start rendering
1509 incomplete content, giving the user a feeling of "it works". This effect is
1510 more noticeable on slower dialup connections. Extremely large documents
1511 may have some impact on the time to load the page where there is filtering
1512 being done. But overall, the difference should be very minimal. If there is a
1513 big impact, then probably some other situation is contributing (like
1514 anti-virus software).
1517 Filtering is automatically disabled for inappropriate MIME types. But note
1518 that if the web server mis-reports the MIME type, then content that should
1519 not be filtered, could be. <application>Privoxy</application> only knows how
1520 to differentiate filterable content because of the MIME type as reported by
1521 the server, or because of some configuration setting that enables/disables
1526 <sect2 renderas="sect3" id="configurl"><title>What are "http://config.privoxy.org/" and
1527 "http://p.p/"?</title>
1529 <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink> is the
1530 address of <application>Privoxy</application>'s built-in user interface, and
1531 <ulink url="http://p.p/">http://p.p/</ulink> is a shortcut for it.
1534 Since <application>Privoxy</application> sits between your web browser and the Internet,
1535 it can simply intercept requests for these addresses and answer them with its built-in
1536 <quote>web server</quote>.
1539 This also makes for a good test for your browser configuration: If entering the
1540 URL <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
1541 takes you to a page saying <quote>This is Privoxy ...</quote>, everything is OK.
1542 If you get a page saying <quote>Privoxy is not working</quote> instead, then
1543 your browser didn't use <application>Privoxy</application> for the request,
1544 hence it could not be intercepted, and you have accessed the <emphasis>real</emphasis>
1545 web site at config.privoxy.org.
1551 out of date 09/02/06 HB
1552 <sect2 renderas="sect3" id="blocklist"><title>Do you still maintain the blocklists?</title>
1554 No. The patterns for blocking now reside (among other things) in the <ulink
1555 url="../user-manual/actions-file.html">actions files</ulink>, which are
1556 actively maintained instead. See next question ...
1560 <sect2 renderas="sect3" id="newads"><title>How can I submit new ads, or report
1563 Please see the <link linkend="contact">Contact section</link> for
1564 various ways to interact with the developers.
1569 <sect2 renderas="sect3" id="newads2"><title>If I do submit missed ads, will
1570 they be included in future updates?</title>
1572 Whether such submissions are eventually included in the
1573 <filename>default.action</filename> configuration file depends on how
1574 significant the issue is. We of course want to address any potential
1575 problem with major, high-profile sites such as <citetitle>Google</citetitle>,
1576 <citetitle>Yahoo</citetitle>, etc. Any site with global or regional reach,
1577 has a good chance of being a candidate. But at the other end of the spectrum
1578 are any number of smaller, low-profile sites such as for local clubs or
1579 schools. Since their reach and impact are much less, they are best handled by
1580 inclusion in the user's <filename>user.action</filename>, and thus would be
1581 unlikely to be included.
1587 <sect2 renderas="sect3" id="noonecares"><title>Why doesn't anyone answer my support
1590 Rest assured that it has been read and considered. Why it is not answered,
1591 could be for various reasons, including no one has a good answer for it, no
1592 one has had time to yet investigate it thoroughly, it has been reported
1593 numerous times already, or because not enough information was provided to help
1594 us help you. Your efforts are not wasted, and we do appreciate them.
1600 <sect2 renderas="sect3" id="ip"><title>How can I hide my IP address?</title>
1602 If you run both the browser and &my-app; locally, you cannot hide your IP
1603 address with <application>Privoxy</application> or ultimately any other
1604 software alone. The server needs to know your IP address so that it knows
1605 where to send the responses back.
1608 There are many publicly usable "anonymous" proxies out there, which
1609 provide a further level of indirection between you and the web server.
1612 However, these proxies are called "anonymous" because you don't need
1613 to authenticate, not because they would offer any real anonymity.
1614 Most of them will log your IP address and make it available to the
1615 authorities in case you violate the law of the country they run in. In fact
1616 you can't even rule out that some of them only exist to *collect* information
1617 on (those suspicious) people with a more than average preference for privacy.
1620 Your best bet is to chain <application>Privoxy</application>
1621 with <ulink url="http://tor.eff.org/">Tor</ulink>,
1622 an <ulink url="http://www.eff.org/">EFF</ulink> supported onion routing system.
1623 The configuration details can be found in
1624 <ulink url="#TOR">How do I use <application>Privoxy</application> together
1625 with <application>Tor</application> section</ulink>
1630 <sect2 renderas="sect3">
1631 <title id="anonforsure">Can Privoxy guarantee I am anonymous?</title>
1633 No. Your chances of remaining anonymous are greatly improved, but unless you
1634 <ulink url="#TOR">chain <application>Privoxy</application> with <application>Tor</application></ulink>
1635 or a similar system and know what you're doing when it comes to configuring
1636 the rest of your system, it would be safest to assume that everything you do
1637 on the Web can be traced back to you.
1640 <application>Privoxy</application> can remove various information about you,
1641 and allows <emphasis>you</emphasis> more freedom to decide which sites
1642 you can trust, and what details you want to reveal. But it neither
1643 hides your IP address, nor can it guarantee that the rest of the system
1644 behaves correctly. There are several possibilities how a web sites can find
1645 out who you are, even if you are using a strict <application>Privoxy</application>
1646 configuration and chained it with <application>Tor</application>.
1649 Most of <application>Privoxy's</application> privacy-enhancing features can be easily subverted
1650 by an insecure browser configuration, therefore you should use a browser that can
1651 be configured to only execute code from trusted sites, and be careful which sites you trust.
1652 For example there is no point in having <application>Privoxy</application>
1653 modify the User-Agent header, if websites can get all the information they want
1654 through JavaScript, ActiveX, Flash, Java etc.
1657 A few browsers disclose the user's email address in certain situations, such
1658 as when transferring a file by FTP. <application>Privoxy</application>
1659 does not filter FTP. If you need this feature, or are concerned about the
1660 mail handler of your browser disclosing your email address, you might
1661 consider products such as <application>NSClean</application>.
1664 Browsers available only as binaries could use non-standard headers to give
1665 out any information they can have access to: see the manufacturer's license
1666 agreement. It's impossible to anticipate and prevent every breach of privacy
1667 that might occur. The professionally paranoid prefer browsers available as
1668 source code, because anticipating their behavior is easier. Trust the source,
1674 <sect2 renderas="sect3">
1675 <title id="proxytest">A test site says I am not using a Proxy.</title>
1677 Good! Actually, they are probably testing for some other kinds of proxies.
1678 Hiding yourself completely would require additional steps.
1682 <sect2 renderas="sect3" id="tor"><title>How do I use Privoxy
1683 together with Tor?</title>
1685 Before you configure <application>Privoxy</application> to use
1686 <ulink url="https://www.torproject.org/">Tor</ulink>,
1687 please follow the <citetitle>User Manual</citetitle> chapters
1688 <ulink url="../user-manual/installation.html">2. Installation</ulink> and
1689 <ulink url="../user-manual/startup.html">5. Startup</ulink> to make sure
1690 <application>Privoxy</application> itself is setup correctly.
1693 If it is, refer to <ulink url="https://www.torproject.org/documentation.html">Tor's
1694 extensive documentation</ulink> to learn how to install <application>Tor</application>,
1695 and make sure <application>Tor</application>'s logfile says that
1696 <quote>Tor has successfully opened a circuit</quote> and it
1697 <quote>looks like client functionality is working</quote>.
1700 If either <application>Tor</application> or <application>Privoxy</application>
1701 isn't working, their combination most likely will neither. Testing them on their
1702 own will also help you to direct problem reports to the right audience.
1703 If <application>Privoxy</application> isn't working, don't bother the
1704 <application>Tor</application> developers. If <application>Tor</application>
1705 isn't working, don't send bug reports to the <application>Privoxy</application> Team.
1708 If you verified that <application>Privoxy</application> and <application>Tor</application>
1709 are working, it is time to connect them. As far as <application>Privoxy</application>
1710 is concerned, <application>Tor</application> is just another proxy that can be reached
1711 by socks4 or socks4a. Most likely you are interested in <application>Tor</application>
1712 to increase your anonymity level, therefore you should use socks4a, to make sure DNS requests are
1713 done through <application>Tor</application> and thus invisible to your local network.
1718 Since <application>Privoxy</application> 3.0.5, its
1719 <ulink url="../user-manual/config.html">main configuration file</ulink>
1720 is already prepared for <application>Tor</application>, if you are using a
1721 default <application>Tor</application> configuration and run it on the same
1722 system as &my-app;, you just have to edit the
1723 <ulink url="../user-manual/config.html#FORWARDING">forwarding section</ulink>
1724 and uncomment the line:
1728 # forward-socks4a / 127.0.0.1:9050 .
1732 This is enough to reach the Internet, but additionally you might want to
1733 uncomment the following forward rules, to make sure your local network is still
1734 reachable through Privoxy:
1738 # forward 192.168.*.*/ .
1739 # forward 10.*.*.*/ .
1740 # forward 127.*.*.*/ .
1744 Unencrypted connections to systems in these address ranges will
1745 be as (un)secure as the local network is, but the alternative is
1746 that your browser can't reach the network at all. Then again,
1747 that may actually be desired and if you don't know for sure
1748 that your browser has to be able to reach the local network,
1749 there's no reason to allow it.
1752 If you want your browser to be able to reach servers in your local
1753 network by using their names, you will need additional exceptions
1754 that look like this:
1758 # forward localhost/ .
1762 Save the modified configuration file and open
1763 <ulink url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status/</ulink>
1764 in your browser, confirm that <application>Privoxy</application> has reloaded its configuration
1765 and that there are no other forward lines, unless you know that you need them. If everything looks good,
1767 <ulink url="https://wiki.torproject.org/wiki/TheOnionRouter/TorFAQ#head-0e1cc2ac330ede8c6ad1ac0d0db0ac163b0e6143">Tor
1768 Faq 4.2</ulink> to learn how to verify that you are really using <application>Tor</application>.
1771 Afterward, please take the time to at least skim through the rest
1772 of <application>Tor's</application> documentation. Make sure you understand
1773 what <application>Tor</application> does, why it is no replacement for
1774 application level security, and why you shouldn't use it for unencrypted logins.
1778 <sect2 renderas="sect3">
1779 <title id="sitebreak">Might some things break because header information or
1780 content is being altered?</title>
1783 Definitely. It is common for sites to use browser type, browser version,
1784 HTTP header content, and various other techniques in order to dynamically
1785 decide what to display and how to display it. What you see, and what I see,
1786 might be very different. There are many, many ways that this can be handled,
1787 so having hard and fast rules, is tricky.
1791 The <quote>User-Agent</quote> is sometimes used in this way to identify
1792 the browser, and adjust content accordingly.
1796 Also, different browsers use different encodings of Russian and Czech
1797 characters, certain web servers convert pages on-the-fly according to the
1798 User Agent header. Giving a <quote>User Agent</quote> with the wrong
1799 operating system or browser manufacturer causes some sites in these languages
1800 to be garbled; Surfers to Eastern European sites should change it to
1801 something closer. And then some page access counters work by looking at the
1802 <quote>Referer</quote> header; they may fail or break if unavailable. The
1803 weather maps of Intellicast have been blocked by their server when no
1804 <quote>Referer</quote> or cookie is provided, is another example. (But you
1805 can forge both headers without giving information away). There are
1806 many other ways things that can go wrong when trying to fool a web server. The
1807 results of which could inadvertently cause pages to load incorrectly,
1808 partially, or even not at all. And there may be no obvious clues as to just
1809 what went wrong, or why. Nowhere will there be a message that says
1810 <quote><emphasis>Turn off <literal>fast-redirects</literal> or else!</emphasis>
1815 Similar thoughts apply to modifying JavaScript, and, to a lesser degree,
1820 If you have problems with a site, you will have to adjust your configuration
1821 accordingly. Cookies are probably the most likely adjustment that may
1822 be required, but by no means the only one.
1828 <sect2 renderas="sect3">
1829 <title id="caching">Can Privoxy act as a <quote>caching</quote> proxy to
1830 speed up web browsing?</title>
1832 No, it does not have this ability at all. You want something like
1833 <ulink url="http://www.squid-cache.org/">Squid</ulink> or
1834 <ulink url="http://www.pps.jussieu.fr/~jch/software/polipo/">Polipo</ulink> for this.
1835 And, yes, before you ask, <application>Privoxy</application> can co-exist
1836 with other kinds of proxies like <application>Squid</application>.
1837 See the <ulink url="../user-manual/config.html#FORWARDING">forwarding
1838 chapter</ulink> in the <ulink url="../user-manual/index.html">user
1839 manual</ulink> for details.
1843 <sect2 renderas="sect3">
1844 <title id="firewall">What about as a firewall? Can Privoxy protect me?</title>
1846 Not in the way you mean, or in the way some firewall vendors claim they can.
1847 <application>Privoxy</application> can help protect your privacy, but can't
1848 protect your system from intrusion attempts. It is, of course, perfectly possible
1849 to use <emphasis>both</emphasis>.
1853 <sect2 renderas="sect3">
1854 <title id="wasted">I have large empty spaces / a checkerboard pattern now where
1855 ads used to be. Why?</title>
1857 It is technically possible to eliminate banners and ads in a way that frees
1858 their allocated page space. This could easily be done by blocking with
1859 <application>Privoxy's</application> filters,
1860 and eliminating the <emphasis>entire</emphasis> image references from the
1864 But, this would consume considerably more CPU resources (IOW, slow things
1865 down), would likely destroy the layout of some web pages which rely on the
1866 banners utilizing a certain amount of page space, and might fail in other
1867 cases, where the screen space is reserved (e.g. by HTML tables for instance).
1868 Also, making ads and banners disappear without any trace complicates
1869 troubleshooting, and would sooner or later be problematic.
1872 The better alternative is to instead let them stay, and block the resulting
1873 requests for the banners themselves as is now the case. This leaves either
1874 empty space, or the familiar checkerboard pattern.
1877 So the developers won't support this in the default configuration, but you
1878 can of course define appropriate filters yourself to achieve this.
1882 <sect2 renderas="sect3">
1883 <title id="ssl">How can Privoxy filter Secure (HTTPS) URLs?</title>
1885 Since secure HTTP connections are encrypted SSL sessions between your browser
1886 and the secure site, and are meant to be reliably <emphasis>secure</emphasis>,
1887 there is little that <application>Privoxy</application> can do but hand the raw
1888 gibberish data though from one end to the other unprocessed.
1891 The only exception to this is blocking by host patterns, as the client needs
1892 to tell <application>Privoxy</application> the name of the remote server,
1893 so that <application>Privoxy</application> can establish the connection.
1894 If that name matches a host-only pattern, the connection will be blocked.
1897 As far as ad blocking is concerned, this is less of a restriction than it may
1898 seem, since ad sources are often identifiable by the host name, and often
1899 the banners to be placed in an encrypted page come unencrypted nonetheless
1900 for efficiency reasons, which exposes them to the full power of
1901 <application>Privoxy</application>'s ad blocking.
1904 <quote>Content cookies</quote> (those that are embedded in the actual HTML or
1905 JS page content, see <literal><ulink
1906 url="../user-manual/actions-file.html#FILTER-CONTENT-COOKIES">filter{content-cookies}</ulink></literal>),
1907 in an SSL transaction will be impossible to block under these conditions.
1908 Fortunately, this does not seem to be a very common scenario since most
1909 cookies come by traditional means.
1914 <sect2 renderas="sect3">
1915 <title id="secure">Privoxy runs as a <quote>server</quote>. How
1916 secure is it? Do I need to take any special precautions?</title>
1918 On Unix-like systems, <application>Privoxy</application> can run as a non-privileged
1919 user, which is how we recommend it be run. Also, by default
1920 <application>Privoxy</application> listens to requests from <quote>localhost</quote>
1924 The server aspect of <application>Privoxy</application> is not itself directly
1925 exposed to the Internet in this configuration. If you want to have
1926 <application>Privoxy</application> serve as a LAN proxy, this will have to
1927 be opened up to allow for LAN requests. In this case, we'd recommend
1928 you specify only the LAN gateway address, e.g. 192.168.1.1, in the main
1929 <application>Privoxy</application> configuration file and check all <ulink
1930 url="../user-manual/config.html#ACCESS-CONTROL">access control and security
1931 options</ulink>. All LAN hosts can then use this as their proxy address
1932 in the browser proxy configuration, but <application>Privoxy</application>
1933 will not listen on any external interfaces. ACLs can be defined in addition,
1934 and using a firewall is always good too. Better safe than sorry.
1939 <sect2 renderas="sect3" id="turnoff">
1940 <title>How can I temporarily disable Privoxy?</title>
1942 The easiest way is to access <application>Privoxy</application> with your
1943 browser by using the remote toggle URL: <ulink
1944 url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>.
1945 See the <ulink url="../user-manual/appendix.html#BOOKMARKLETS">Bookmarklets section</ulink>
1946 of the <citetitle>User Manual</citetitle> for an easy way to access this
1947 feature. Note that this is a feature that may need to be enabled in the main
1948 <filename>config</filename> file.
1953 <sect2 renderas="sect3" id="reallyoff">
1954 <title>When <quote>disabled</quote> is Privoxy totally
1955 out of the picture?</title>
1957 No, this just means all optional filtering and actions are disabled.
1958 <application>Privoxy</application> is still acting as a proxy, but just not
1959 doing any of the things that <application>Privoxy</application> would
1960 normally be expected to do. It is still a <quote>middle-man</quote> in
1961 the interaction between your browser and web sites. See below to bypass
1966 <sect2 renderas="sect3" id="turnoff2">
1967 <title>How can I tell Privoxy to totally ignore certain sites?</title>
1969 Bypassing a proxy, or proxying based on arbitrary criteria, is purely a browser
1970 configuration issue, not a &my-app; issue. Modern browsers typically do have
1971 settings for not proxying certain sites. Check your browser's help files.
1976 <sect2 renderas="sect3" id="crunch">
1977 <title>My logs show Privoxy <quote>crunches</quote>
1978 ads, but also its own internal CGI pages. What is a <quote>crunch</quote>?</title>
1980 A <quote>crunch</quote> simply means <application>Privoxy</application> intercepted
1981 <emphasis>something</emphasis>, nothing more. Often this is indeed ads or
1982 banners, but <application>Privoxy</application> uses the same mechanism for
1983 trapping requests for its own internal pages. For instance, a request for
1984 <application>Privoxy's</application> configuration page at: <ulink
1985 url="http://config.privoxy.org">http://config.privoxy.org</ulink>, is
1986 intercepted (i.e. it does not go out to the 'net), and the familiar CGI
1987 configuration is returned to the browser, and the log consequently will show
1988 a <quote>crunch</quote>.
1991 Since version 3.0.7, Privoxy will also log the crunch reason.
1992 If you are using an older version you might want to upgrade.
1996 <sect2 renderas="sect3" id="downloads">
1997 <title>Can Privoxy effect files that I download
1998 from a webserver? FTP server?</title>
2000 From the webserver's perspective, there is no difference between
2001 viewing a document (i.e. a page), and downloading a file. The same is true of
2002 <application>Privoxy</application>. If there is a match for a <literal><ulink
2003 url="../user-manual/actions-file.html#BLOCK">block</ulink></literal> pattern,
2004 it will still be blocked, and of course this is obvious.
2007 Filtering is potentially more of a concern since the results are not always
2008 so obvious, and the effects of filtering are there whether the file is simply
2009 viewed, or downloaded. And potentially whether the content is some obnoxious
2010 advertisement, or Mr. Jimmy's latest/greatest source code jewel. Of course,
2011 one of these presumably is <quote>bad</quote> content that we don't want, and
2012 the other is <quote>good</quote> content that we do want.
2013 <application>Privoxy</application> is blind to the differences, and can only
2014 distinguish <quote>good from bad</quote> by the configuration parameters
2015 <emphasis>we</emphasis> give it.
2018 <application>Privoxy</application> knows the differences in files according
2019 to the <quote>Content Type</quote> as reported by the webserver. If this is
2020 reported accurately (e.g. <quote>application/zip</quote> for a zip archive),
2021 then <application>Privoxy</application> knows to ignore these where
2022 appropriate. <application>Privoxy</application> potentially can filter HTML
2023 as well as plain text documents, subject to configuration parameters of
2024 course. Also, documents that are of an unknown type (generally assumed to be
2025 <quote>text/plain</quote>) can be filtered, as will those that might be
2026 incorrectly reported by the webserver. If such a file is a downloaded file
2027 that is intended to be saved to disk, then any content that might have been
2028 altered by filtering, will be saved too, for these (probably rare) cases.
2031 Note that versions later than 3.0.2 do NOT filter document types reported as
2032 <quote>text/plain</quote>. Prior to this, <application>Privoxy</application>
2033 did filter this document type.
2036 In short, filtering is <quote>ON</quote> if a) the content type as reported
2037 by the webserver is appropriate <emphasis>and</emphasis> b) the configuration
2038 allows it (or at least does not disallow it). That's it. There is no magic
2039 cookie anywhere to say this is <quote>good</quote> and this is
2040 <quote>bad</quote>. It's the configuration that lets it all happen or not.
2043 If you download text files, you probably do not want these to be filtered,
2044 particularly if the content is source code, or other critical content. Source
2045 code sometimes might be mistaken for Javascript (i.e. the kind that might
2046 open a pop-up window). It is recommended to turn off filtering for download
2047 sites (particularly if the content may be plain text files and you are using
2048 version 3.0.2 or earlier) in your <filename>user.action</filename> file. And
2049 also, for any site or page where making <emphasis>any</emphasis> changes at
2050 all to the content is to be avoided.
2053 <application>Privoxy</application> does not do FTP at all, only HTTP
2054 and HTTPS (SSL) protocols, so please don't try.
2058 <sect2 renderas="sect3" id="downloads2">
2059 <title>I just downloaded a Perl script, and Privoxy
2060 altered it! Yikes, what is wrong!</title>
2066 <sect2 renderas="sect3" id="hostsfile">
2067 <title>Should I continue to use a <quote>HOSTS</quote> file for ad-blocking?</title>
2069 One time-tested technique to defeat common ads is to trick the local DNS
2070 system by giving a phony IP address for the ad generator in the local
2071 <filename>HOSTS</filename> file, typically using <literal>127.0.0.1</literal>, aka
2072 <literal>localhost</literal>. This effectively blocks the ad.
2075 There is no reason to use this technique in conjunction with
2076 <application>Privoxy</application>. <application>Privoxy</application>
2077 does essentially the same thing, much more elegantly and with much more
2078 flexibility. A large <filename>HOSTS</filename> file, in fact, not only
2079 duplicates effort, but may get in the way and seriously slow down your system.
2080 It is recommended to remove such entries from your <filename>HOSTS</filename> file. If you think
2081 your hosts list is neglected by <application>Privoxy's </application>
2082 configuration, consider adding your list to your <filename>user.action</filename> file:
2089 ads.galore.example.com
2090 etc.example.com</screen>
2094 <sect2 renderas="sect3" id="seealso">
2095 <title>Where can I find more information about Privoxy
2096 and related issues?</title>
2097 <!-- Include seealso.sgml boilerplate: -->
2099 <!-- end boilerplate -->
2104 <ulink url="../user-manual/seealso.html">user-manual</ulink> for
2110 <sect2 renderas="sect3" id="microsuck">
2111 <title>I've noticed that Privoxy changes <quote>Microsoft</quote> to
2112 <quote>MicroSuck</quote>! Why are you manipulating my browsing?</title>
2115 We're not. The text substitutions that you are seeing are disabled
2116 in the default configuration as shipped. You have either manually
2117 activated the <quote><literal>fun</literal></quote> filter which
2118 is clearly labeled <quote>Text replacements for subversive browsing
2119 fun!</quote> or you are using an older Privoxy version and have implicitly
2120 activated it by choosing the <quote>Adventuresome</quote> profile in the
2121 web-based editor. Please upgrade!
2125 <sect2 renderas="sect3" id="valid">
2126 <title>Does Privoxy produce <quote>valid</quote> HTML (or XHTML)?</title>
2129 Privoxy generates HTML in both its own <quote>templates</quote>, and possibly
2130 whenever there are text substitutions via a &my-app; filter. While this
2131 should always conform to the HTML 4.01 specifications, it has not been
2132 validated against this or any other standard.
2140 <!-- ~~~~~ New section ~~~~~ -->
2142 <sect1 id="trouble">
2143 <title>Troubleshooting</title>
2145 <sect2 renderas="sect3">
2146 <title id="refused">I cannot connect to any websites. Or, I am getting
2147 <quote>connection refused</quote> message with every web page. Why?</title>
2149 There are several possibilities:
2154 <application>Privoxy</application> is not running. Solution: verify
2155 that &my-app; is installed correctly, has not crashed, and is indeed running.
2156 Turn on <application>Privoxy's</application> logging, and look at the logs to see what they say.
2158 <listitem><para>Or your browser is configured for a different port than what
2159 <application>Privoxy</application> is using. Solution: verify that &my-app;
2160 and your browser are set to the same port (<literal>listen-address</literal>).
2162 <listitem><para>Or if using a forwarding rule, you have a configuration problem or a
2163 problem with a host in the forwarding chain. Solution: temporarily alter your
2164 configuration and take the forwarders out of the equation.
2167 Or you have a firewall that is interfering and blocking you. Solution:
2168 try disabling or removing the firewall as a simple test.
2175 <!-- ~~~~~ New section ~~~~~ -->
2176 <sect2 renderas="sect3" id="error503">
2177 <title>Why am I getting a 503 Error (WSAECONNREFUSED) on every page?</title>
2179 More than likely this is a problem with your TCP/IP networking. ZoneAlarm has
2180 been reported to cause this symptom -- even if not running! The solution is
2181 to either fight the ZA configuration, or uninstall ZoneAlarm, and then find
2182 something better behaved in its place. Other personal firewall type products
2183 may cause similar type problems if not configured correctly.
2187 <sect2 renderas="sect3">
2188 <title id="flushit">I just added a new rule, but the steenkin ad is
2189 still getting through. How?</title>
2191 If the ad had been displayed before you added its URL, it will probably be
2192 held in the browser's cache for some time, so it will be displayed without
2193 the need for any request to the server, and <application>Privoxy</application>
2194 will not be involved. Flush the browser's caches, and then try again.
2198 If this doesn't help, you probably have an error in the rule you
2199 applied. Try pasting the full URL of the offending ad into <ulink
2200 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
2201 and see if it really matches your new rule. Blocking ads is like blocking
2202 spam: a lot of tinkering is required to stay ahead of the game. And
2203 remember you need to block the URL of the ad in question, which may be
2204 entirely different from the site URL itself. Most ads are hosted on different
2205 servers than the main site itself. If you right-click on the ad, you should
2206 be able to get all the relevant information you need. Alternately, you can
2207 find the correct URL by looking at <application>Privoxy's</application> logs
2208 (you may need to enable logging in the main config file if its disabled).
2211 Below is a slightly modified real-life log snippet that originates with one
2212 requested URL: <literal>www.example.com</literal> (name of site was changed
2213 for this example, the number of requests is real). You can see in this the
2214 complexity of what goes into making up this one <quote>page</quote>. There
2215 are eight different domains involved here, with thirty two separate URLs
2216 requested in all, making up all manner of images, Shockwave Flash,
2217 JavaScript, CSS stylesheets, scripts, and other related content. Some of this
2218 content is obviously <quote>good</quote> or <quote>bad</quote>, but not all.
2219 Many of the more questionable looking requests, are going to outside domains
2220 that seem to be identifying themselves with suspicious looking names, making
2221 our job a little easier. &my-app; has <quote>crunched</quote> (meaning caught
2222 and BLOCKED) quite a few items in this example, but perhaps missed a few as well.
2227 Request: www.example.com/
2228 Request: www.example.com/favicon.ico
2229 Request: img.example.com/main.css
2230 Request: img.example.com/sr.js
2231 Request: example.betamarker.com/example.html
2232 Request: www.lik-sang.com/Banners/bestsellers/skyscraper.php?likref=BSellers
2233 Request: img.example.com/pb.png
2234 Request: www.google-analytics.com/urchin.js crunch! (Blocked)
2235 Request: www.advertising-department.com/ats/switch.ps.php?26856 crunch! (Blocked)
2236 Request: img.example.com/p.gif
2237 Request: www.popuptraffic.com/assign.php?l=example&mode=behind crunch! (Blocked)
2238 Request: www.popuptraffic.com/scripts/popup.php?hid=5c3cf&tmpl=PBa.tmpl crunch! (Blocked)
2239 Request: www.popuptraffic.com/assign.php?l=example crunch! (Blocked)
2240 Request: www.lik-sang.com/Banners/best_sellers/best_sellers.css
2241 Request: www.adtrak.net/adx.js crunch! (Blocked)
2242 Request: img.example.com/hbg.gif
2243 Request: img.example.com/example.jpg
2244 Request: img.example.com/mt.png
2245 Request: img.example.com/mm.png
2246 Request: img.example.com/mb.png
2247 Request: www.popuptraffic.com/scripts/popup.php?hid=a71b91fa5&tmpl=Ua.tmp crunch! (Blocked)
2248 Request: www.example.com/tracker.js
2249 Request: www.lik-sang.com/Banners/best_sellers/lsi_head.gif
2250 Request: www.adtrak.net/adjs.php?n=020548130&what=zone:61 crunch! (Blocked)
2251 Request: www.adtrak.net/adjs.php?n=463594413&what=zone:58&source=Ua crunch! (Blocked)
2252 Request: www.lik-sang.com/Banners/best_sellers/bottomani.swf
2253 Request: mmm.elitemediagroup.net/install.php?allowpop=no&popupmincook=0&allowsp2=1 crunch! (Blocked)
2254 Request: www.example.com/tracker.js?screen=1400x1050&win=962x693
2255 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=61 crunch! (Blocked)
2256 Request: 66.70.21.80/scripts/click.php?hid=5c3cf599a9efd0320d26&si
2257 Request: 66.70.21.80/img/pixel.gif
2258 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=58&source=Ua&block=86400 crunch! (Blocked)
2259 Request: 66.70.21.80/scripts/click.php?hid=a71b9f6504b0c5681fa5&si=Ua
2264 Despite 12 out of 32 requests being blocked, the page looked, and seemed to
2265 behave perfectly <quote>normal</quote> (minus some ads, of course).
2270 <sect2 id="badsite" renderas="sect3">
2271 <title >One of my favorite sites does not work with Privoxy.
2272 What can I do?</title>
2275 First verify that it is indeed a <application>Privoxy</application> problem,
2276 by toggling off <application>Privoxy</application> through <ulink
2277 url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>
2278 (the toggle feature may need to be enabled in the main
2279 <filename>config</filename>),
2280 and then shift-reloading the problem page (i.e. holding down the shift key
2281 while clicking reload. Alternatively, flush your browser's disk and memory
2286 If the problem went away, we know we have a configuration related problem.
2288 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
2289 and paste the full URL of the page in question into the prompt. See which
2290 actions are being applied to the URL, and which matches in which actions
2291 files are responsible for that. It might be helpful also to look at your logs
2292 for this site too, to see what else might be happening (note: logging may need
2293 to be enabled in the main config file). Many sites are
2294 complex and require a number of related pages to help present their content.
2295 Look at what else might be used by the page in question, and what of that
2296 might be <emphasis>required</emphasis>.
2297 Now, armed with this information, go to
2299 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
2300 and select the appropriate actions files for editing. </para>
2302 You can now either look for a section which disables the actions that
2303 you suspect to cause the problem and add a pattern for your site there,
2304 or make up a completely new section for your site. In any case, the recommended
2305 way is to disable only the prime suspect, reload the problem page, and only
2306 if the problem persists, disable more and more actions until you have
2307 identified the culprit. You may or may not want to turn the other actions
2308 on again. Remember to flush your browser's caches in between any such changes!
2311 Alternately, if you are comfortable with a text editor, you can accomplish
2312 the same thing by editing the appropriate actions file. Probably the easiest
2313 way to deal with such problems when editing by hand is to add your
2314 site to a <literal>{ fragile }</literal> section in <filename>user.action</filename>,
2315 which is an alias that turns off most <quote>dangerous</quote>
2316 actions, but is also likely to turn off more actions then needed, and thus lower
2317 your privacy and protection more than necessary,
2320 Troubleshooting actions is discussed in more detail in the <ulink
2321 url="../user-manual/appendix.html#ACTIONSANAT">User Manual appendix,
2322 Troubleshooting: the Anatomy of an Action</ulink>.
2323 There is also an <ulink
2324 url="../user-manual/actions-file.html#ACT-EXAMPLES">actions tutorial</ulink>
2325 with general configuration information and examples.
2328 As a last resort, you can always see if your browser has a setting that will
2329 bypass the proxy setting for selective sites. Modern browsers can do this.
2335 <!-- ~~~~~ New section ~~~~~ -->
2336 <sect2 id="dun" renderas="sect3">
2337 <title>After installing Privoxy, I have to log in
2338 every time I start IE. What gives?</title>
2341 This is a quirk that effects the installation of
2342 <application>Privoxy</application>, in conjunction with Internet Explorer and
2343 Internet Connection Sharing on Windows 2000 and Windows XP. The symptoms may
2344 appear to be corrupted or invalid DUN settings, or passwords.
2348 When setting up an NT based Windows system with
2349 <application>Privoxy</application> you may find that things do not seem to be
2350 doing what you expect. When you set your system up you will probably have set
2351 up Internet Connection Sharing (ICS) with Dial up Networking (DUN) when
2352 logged in with administrator privileges. You will probably have made this DUN
2353 connection available to other accounts that you may have set-up on your
2354 system. E.g. Mum or Dad sets up the system and makes accounts suitably
2355 configured for the kids.
2359 When setting up <application>Privoxy</application> in this environment you
2360 will have to alter the proxy set-up of Internet Explorer (IE) for the
2361 specific DUN connection on which you wish to use
2362 <application>Privoxy</application>. When you do this the ICS DUN set-up
2363 becomes user specific. In this instance you will see no difference if you
2364 change the DUN connection under the account used to set-up the connection.
2365 However when you do this from another user you will notice that the DUN
2366 connection changes to make available to "Me only". You will also find that
2367 you have to store the password under each different user!
2371 The reason for this is that each user's set-up for IE is user specific. Each
2372 set-up DUN connection and each LAN connection in IE store the settings for
2373 each user individually. As such this enforces individual configurations
2374 rather than common ones. Hence the first time you use a DUN connection after
2375 re-booting your system it may not perform as you expect, and prompt you for
2376 the password. Just set and save the password again and all should be OK.
2380 [Thanks to Ray Griffith for this submission.]
2385 <!-- ~~~~~ New section ~~~~~ -->
2386 <sect2 id="ftp" renderas="sect3">
2387 <title>I cannot connect to any FTP sites. Privoxy
2388 is blocking me.</title>
2390 <application>Privoxy</application> cannot act as a proxy for FTP traffic,
2391 so do not configure your browser to use <application>Privoxy</application>
2392 as an FTP proxy. The same is true for <emphasis>any protocol other than HTTP
2393 or HTTPS (SSL)</emphasis>.
2396 Most browsers understand FTP as well as HTTP. If you connect to a site, with
2397 a URL like <literal>ftp://ftp.example.com</literal>, your browser is making
2398 an FTP connection, and not a HTTP connection. So while your browser may
2399 speak FTP, <application>Privoxy</application> does not, and cannot proxy
2403 To complicate matters, some systems may have a generic <quote>proxy</quote>
2404 setting, which will enable various protocols, including
2405 <emphasis>both</emphasis> HTTP and FTP proxying! So it is possible to
2406 accidentally enable FTP proxying in these cases. And of course, if this
2407 happens, <application>Privoxy</application> will indeed cause problems since
2408 it does not know FTP. <![%p-newstuff;[Newer version will give a sane error
2409 message if a FTP connection is attempted.]]> Just disable the FTP setting
2410 and all will be well again.
2413 Will <application>Privoxy</application> ever proxy FTP traffic? Unlikely.
2414 There just is not much reason, and the work to make this happen is more than
2419 <!-- ~~~~~ New section ~~~~~ -->
2420 <sect2 id="osxie" renderas="sect3">
2421 <title>In Mac OSX, I can't configure Microsoft Internet Explorer to use
2422 Privoxy as the HTTP proxy.</title>
2424 Microsoft Internet Explorer (in versions like 5.1) respects system-wide
2425 network settings. In order to change the HTTP proxy, open System
2426 Preferences, and click on the Network icon. In the settings pane that
2427 comes up, click on the Proxies tab. Ensure the "Web Proxy (HTTP)" checkbox
2428 is checked and enter <literal>127.0.0.1</literal> in the entry field.
2429 Enter <literal>8118</literal> in the Port field. The next time you start
2430 IE, it should reflect these values.
2434 <!-- ~~~~~ New section ~~~~~ -->
2435 <sect2 renderas="sect3" id="osxuninstall">
2436 <title>In Mac OSX, I dragged the Privoxy folder to the trash in order to
2437 uninstall it. Now the finder tells me I don't have sufficient privileges to
2438 empty the trash.</title>
2440 Just dragging the <application>Privoxy</application> folder to the trash is
2441 not enough to delete it. <application>Privoxy</application> supplies an
2442 <application>uninstall.command</application> file that takes care of
2443 these details. Open the trash, drag the <application>uninstall.command</application>
2444 file out of the trash and double-click on it. You will be prompted for
2445 confirmation and the administration password.
2448 The trash may still appear full after this command; emptying the trash
2449 from the desktop should make it appear empty again.
2454 <!-- ~~~~~ New section ~~~~~ -->
2455 <sect2 renderas="sect3" id="osximages">
2456 <title>In Mac OSX Panther (10.3), images often fail to load and/or I
2457 experience random delays in page loading. I'm using
2458 <literal>localhost</literal> as my browser's proxy setting.</title>
2460 We believe this is due to an IPv6-related bug in OSX, but don't fully
2461 understand the issue yet. In any case, changing the proxy setting to
2462 <literal>127.0.0.1</literal> instead of <literal>localhost</literal>
2463 works around the problem.
2467 <!-- ~~~~~ New section ~~~~~ -->
2468 <sect2 renderas="sect3" id="blankpage">
2469 <title>I get a completely blank page at one site. <quote>View Source</quote>
2470 shows only: <markup><![CDATA[<html><body></body></html>]]></markup>. Without
2471 Privoxy the page loads fine.</title>
2473 Chances are that the site suffers from a bug in
2474 <ulink url="http://www.php.net/"><application>PHP</application></ulink>,
2475 which results in empty pages being sent if the client explicitly requests
2476 an uncompressed page, like <application>Privoxy</application> does.
2477 This bug has been fixed in PHP 4.2.3.
2480 To find out if this is in fact the source of the problem, try adding
2481 the site to a <literal>-prevent-compression</literal> section in
2482 <filename>user.action</filename>:
2485 # Make exceptions for ill-behaved sites:
2487 {-prevent-compression}
2488 .example.com</screen>
2490 If that works, you may also want to report the problem to the
2491 site's webmasters, telling them to use zlib.output_compression
2492 instead of ob_gzhandler in their PHP applications (workaround)
2493 or upgrade to PHP 4.2.3 or later (fix).
2497 <sect2 renderas="sect3" id="nohostname">
2498 <title>My logs show many <quote>Unable to get my own hostname</quote> lines.
2501 <application>Privoxy</application> tries to get the hostname of the system
2502 its running on from the IP address of the system interface it is bound to
2503 (from the <filename>config</filename> file
2504 <emphasis>listen-address</emphasis> setting). If the system cannot supply
2505 this information, <application>Privoxy</application> logs this condition.
2508 Typically, this would be considered a minor system configuration error. It is
2509 not a fatal error to <application>Privoxy</application> however, but may
2510 result in a much slower response from <application>Privoxy</application> on
2511 some platforms due to DNS timeouts.
2514 This can be caused by a problem with the local <filename>HOSTS</filename>
2515 file. If this file has been changed from the original, try reverting it to
2516 see if that helps. Make sure whatever name(s) are used for the local system,
2517 that they resolve both ways.
2521 <sect2 renderas="sect3" id="inuse">
2522 <title>When I try to launch Privoxy, I get an
2523 error message <quote>port 8118 is already in use</quote> (or similar wording).
2526 Port 8118 is <application>Privoxy's</application> default TCP
2527 <quote>listening</quote> port. Typically this message would mean that there
2528 is already one instance of <application>Privoxy</application> running, and
2529 your system is actually trying to start a second
2530 <application>Privoxy</application> on the same port, which will not work.
2531 (You can have multiple instances but they must be assigned different ports.)
2532 How and why this might happen varies from platform to platform, but you need
2533 to check your installation and start-up procedures.
2537 <sect2 renderas="sect3" id="demoronizer">
2539 Pages with UTF-8 fonts are garbled.
2542 This is caused by the <quote>demoronizer</quote> filter. You should either
2543 upgrade <application>Privoxy</application>, or at least upgrade to the most
2544 recent <filename>default.action</filename> file available from <ulink
2545 url="http://sourceforge.net/project/showfiles.php?group_id=11118">SourceForge</ulink>.
2546 Or you can simply disable the demoronizer filter.
2550 <sect2 renderas="sect3" id="demoronizer2">
2552 Why are binary files (such as images) corrupted when Privoxy
2556 This may also be caused by the <quote>demoronizer</quote> filter,
2557 in conjunction with a web server that is misreporting the content type. Binary
2558 files are exempted from <application>Privoxy's</application> filtering
2559 (unless the web server by mistake says the file is something else). Either
2560 upgrade <application>Privoxy</application>, or go to the most recent
2561 <filename>default.action</filename> file available from <ulink
2562 url="http://sourceforge.net/project/showfiles.php?group_id=11118">SourceForge</ulink>.
2566 <sect2 renderas="sect3" id="demoronizer3">
2568 What is the <quote>demoronizer</quote> and why is it there?
2571 The original demoronizer was a Perl script that cleaned up HTML pages which
2572 were created with certain Microsoft products. MS has used proprietary extensions
2573 to standardized font encodings (ISO 8859-1), which has caused problems for pages
2574 that are viewed with non-Microsoft products (and are expecting to see a
2575 standard set of fonts). The demoronizer corrected these errors so the pages
2576 displayed correctly. <application>Privoxy</application> borrowed from this
2577 script, introducing a filter based on the original demoronizer, which in turn could
2578 correct these errors on the fly.
2581 But this is only needed in some situations, and will cause serious problems in some
2585 If you are using Microsoft products, you do not need it. If you need to view
2586 pages with UTF-8 characters (such as Cyrillic or Chinese), then it will
2587 cause corruption of the fonts, and thus <emphasis>should not be on</emphasis>.
2590 On the other hand, if you use non-Microsoft products, and you occasionally
2591 notice weird characters on pages, you might want to try it.
2595 <sect2 renderas="sect3" id="windowopen">
2597 Why do I keep seeing <quote>PrivoxyWindowOpen()</quote> in raw source code?
2600 <application>Privoxy</application> is attempting to disable malicious
2601 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink>
2602 in this case, with the <literal>unsolicited-popups</literal>
2603 filter. <application>Privoxy</application> cannot tell very well
2604 <quote>good</quote> code snippets from <quote>bad</quote> code snippets.
2607 If you see this in HTML source, and the page displays without problems, then
2608 this is good, and likely some pop-up window was disabled. If you see this
2609 where it is causing a problem, such as a downloaded program source code file,
2610 then you should set an exception for this site or page such that the
2611 integrity of the page stays in tact by disabling all filtering.
2615 <sect2 renderas="sect3" id="dnserrors">
2617 I am getting too many DNS errors like <quote>404 No Such Domain</quote>. Why
2618 can't Privoxy do this better?
2621 There are potentially several factors here. First of all, the DNS resolution
2622 is done by the underlying operating system -- not
2623 <application>Privoxy</application> itself. <application>Privoxy</application>
2624 merely initiates the process and hands it off, and then later reports
2625 whatever the outcome was. And tries to give a coherent message if there seems
2626 to be a problem. In some cases, this might otherwise be mitigated by the
2627 browser itself which might try some work-arounds and alternate approaches (e.g
2628 adding <quote>www.</quote> to the URL). In other cases, if
2629 <application>Privoxy</application> is being chained with another proxy, this
2630 could complicate the issue, and cause undue
2631 delays and timeouts. In the case of a <quote>socks4a</quote> proxy, the socks
2632 server handles all the DNS. <application>Privoxy</application> would just be
2633 the <quote>messenger</quote> which is reporting whatever problem occurred
2634 downstream, and not the root cause of the error.
2638 In any case, newer versions include various improvements to help
2639 <application>Privoxy</application> better handle these cases.
2643 <sect2 renderas="sect3" id="allcpu">
2645 At one site Privoxy just hangs, and starts taking
2646 all CPU. Why is this?
2649 This is probably a manifestation of the <quote>100% cpu</quote> problem that
2650 occurs on pages containing many (thousands upon thousands) of blank lines. The blank lines
2651 are in the raw HTML source of the page, and the browser just ignores them. But the
2652 pattern matching in <application>Privoxy's</application> page filtering
2653 mechanism is trying to match against absurdly long strings and this becomes
2654 very CPU-intensive, taking a long, long time to complete. Until a better
2655 solution comes along, disable filtering on these pages, particularly the
2656 <literal>js-annoyances</literal> and <literal>unsolicited-popups</literal>
2661 <sect2 renderas="sect3" id="slowcrawl">
2662 <title>I just installed Privoxy, and all my
2663 browsing has slowed to a crawl. What gives? </title>
2665 This should not happen, and for the overwhelming number of users world-wide,
2666 it does not happen. I would suspect some inadvertent interaction of software
2667 components such as anti-virus software, spyware protectors, personal
2668 firewalls or similar components. Try disabling (or uninstalling) these one
2669 at a time and see if that helps.
2673 <sect2 renderas="sect3" id="preventcomp">
2674 <title>Why do my filters work on some sites but not on others? </title>
2676 It's probably due to compression. It is a common practice for web servers to
2677 send their content <quote>compressed</quote> in order to speed things up, and
2678 then let the browser <quote>uncompress</quote> them. When compiled with zlib support
2679 &my-app; can decompress content before filtering, otherwise you may want to enable
2681 url="../user-manual/actions-file.html#PREVENT-COMPRESSION">prevent-compression</ulink>.
2688 <!-- ~~~~~ New section ~~~~~ -->
2689 <sect1 id="contact"><title>Contacting the developers, Bug Reporting and Feature Requests</title>
2690 <!-- Include contacting.sgml -->
2692 <!-- end contacting -->
2695 <!-- ~~~~~ New section ~~~~~ -->
2696 <sect1 id="copyright"><title>Privoxy Copyright, License and History</title>
2698 <!-- Include copyright.sgml -->
2704 Portions of this document are <quote>borrowed</quote> from the original
2705 <application>Junkbuster</application> (tm) FAQ, and modified as
2706 appropriate for <application>Privoxy</application>.
2709 <!-- ~~~~~ New section ~~~~~ -->
2710 <sect2><title>License</title>
2711 <!-- Include copyright.sgml: -->
2713 <!-- end copyright -->
2715 <!-- ~ End section ~ -->
2717 <!-- ~~~~~ New section ~~~~~ -->
2718 <sect2><title>History</title>
2719 <!-- Include history.sgml -->
2725 <!-- ~ End section ~ -->
2728 <!-- ~~~~~ New section ~~~~~ -->
2730 <sect1 id="seealso"><title>See also</title>
2732 <!-- Include seealso.sgml -->
2743 Tue 09/11/01 06:38:14 PM EST: Test SGML doc by Hal Burgiss.
2745 This program is free software; you can redistribute it
2746 and/or modify it under the terms of the GNU General
2747 Public License as published by the Free Software
2748 Foundation; either version 2 of the License, or (at
2749 your option) any later version.
2751 This program is distributed in the hope that it will
2752 be useful, but WITHOUT ANY WARRANTY; without even the
2753 implied warranty of MERCHANTABILITY or FITNESS FOR A
2754 PARTICULAR PURPOSE. See the GNU General Public
2755 License for more details.
2757 The GNU General Public License should be included with
2758 this file. If not, you can view it at
2759 http://www.gnu.org/copyleft/gpl.html
2760 or write to the Free Software Foundation, Inc.,
2761 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
2764 Revision 2.33 2007/11/15 03:30:20 hal9
2765 Results of spell check.
2767 Revision 2.32 2007/11/13 03:03:42 hal9
2768 Various changes to reflect new features and revised configuration for the
2771 Revision 2.31 2007/11/05 02:34:53 hal9
2772 Various changes in preparation for the upcoming release. Much yet to be done.
2774 Revision 2.30 2007/11/04 15:16:40 hal9
2777 Revision 2.29 2007/11/04 15:12:47 hal9
2778 Various minor adjustments.
2780 Revision 2.28 2007/10/27 15:14:16 fabiankeil
2781 Change Tor links to use the new domain torproject.org.
2783 Revision 2.27 2007/10/22 19:47:05 fabiankeil
2784 - Bump version and copyright.
2785 - Adjust Tor section to make it clear that forward exceptions
2786 aren't required and may not even be desired.
2787 - A bunch of other minor rewordings.
2788 - Fix markup problems Roland noticed (hopefully without adding new ones).
2790 Revision 2.26 2007/08/05 15:37:55 fabiankeil
2791 - Don't claim that thousands of people read our code.
2792 - Specify the GPL version and link to GPLv2 instead of v3.
2793 - Note that configuration syntax may change between releases.
2794 - Mention zlib support.
2795 - Answer the "transparent proxy" question properly.
2796 - Add "intercepting proxy" entry.
2798 - Rephrase some other sentences for various reasons.
2800 Revision 2.25 2007/07/18 11:00:34 hal9
2801 Add misc note about valid mark-up in Privoxy.
2803 Revision 2.24 2006/11/14 01:57:46 hal9
2804 Dump all docs prior to 3.0.6 release. Various minor changes to faq and user
2807 Revision 2.23 2006/10/21 22:19:52 hal9
2808 Two new FAQs, a rewrite or two, and some touch ups.
2810 Revision 2.22 2006/10/14 20:33:10 hal9
2811 Three new FAQ's re: templates and blocking, and various minor touch-ups/improvements.
2813 Revision 2.21 2006/10/03 14:40:51 fabiankeil
2814 Added links from the Tor faq to the
2815 configuration chapter in the User Manual.
2817 Revision 2.20 2006/09/26 10:12:37 fabiankeil
2820 Revision 2.19 2006/09/22 10:54:32 hal9
2821 Change references to 3.0.4 to 3.0.5 and minor adjustments.
2823 Revision 2.18 2006/09/22 01:27:55 hal9
2824 Final commit of probably various minor changes here and there. Unless
2825 something changes this should be ready for pending release.
2827 Revision 2.17 2006/09/17 14:56:32 hal9
2828 This includes yet several more new FAQs, some improved wording, enhanced
2829 mark-up, various hyper links to wikipedia to explain key terminology to the
2830 uninitiated, etc. This is ready for release IMO pending final tagging of cvs
2831 and Privoxy version stamping.
2833 Revision 2.16 2006/09/10 15:30:46 hal9
2836 Revision 2.15 2006/09/08 23:05:07 hal9
2837 Fix broken links. Add faq on hosts files. Move most of new windows service
2838 feature to user manual and reference in faq. Various other small changes.
2840 Revision 2.14 2006/09/05 13:25:12 david__schmidt
2841 Add Windows service invocation stuff (duplicated) in FAQ and in user manual under Windows startup. One probably ought to reference the other.
2843 Revision 2.13 2006/09/04 19:20:33 fabiankeil
2844 Adjusted anonymity related sections to match reality.
2845 Added a section about using Privoxy with Tor.
2847 Revision 2.12 2006/09/03 14:15:30 hal9
2848 Various updates, including 7 or 8 new FAQs, and updates/changes to various
2849 other ones to better reflect improvements, additions and changes for the
2850 upcoming release. This is close to final form for 3.0.4 IMHO.
2852 Revision 2.11 2006/07/18 14:48:50 david__schmidt
2853 Reorganizing the repository: swapping out what was HEAD (the old 3.1 branch)
2854 with what was really the latest development (the v_3_0_branch branch)
2856 Revision 1.61.2.41 2004/04/05 13:44:05 oes
2857 Fixed allow-all-cookies alias name; closes SR #929746
2859 Revision 1.61.2.40 2004/01/30 17:00:33 oes
2860 Added OSX Panther problem
2862 Revision 1.61.2.39 2004/01/29 22:53:08 hal9
2863 Minor changes for exempting docs of text/plain. Change copyright date.
2865 Revision 1.61.2.38 2003/12/10 03:39:45 hal9
2866 Added FAQs for: demoronizer, related problems and why its included. Also,
2867 port 8118 already in use questions, and PrivoxyWindowOpen() questions. All in
2868 troubleshooting section.
2870 Revision 1.61.2.37 2003/10/17 11:01:50 oes
2871 Added Q&A for "not being used" page problem
2873 Revision 1.61.2.36 2003/06/26 23:49:20 hal9
2874 More on the filter/source code problem.
2876 Revision 1.61.2.35 2003/06/26 13:38:08 hal9
2877 Add FAQ on whether configuring Privoxy is necessary or not.
2879 Revision 1.61.2.34 2003/06/26 03:00:03 hal9
2880 Sorry, found another copyright date.
2882 Revision 1.61.2.33 2003/06/26 02:57:05 hal9
2883 Fix typo (finally!) and very minor modifications.
2885 Revision 1.61.2.32 2003/06/26 02:52:04 hal9
2888 Revision 1.61.2.31 2003/06/25 01:27:51 hal9
2889 Fix copyright, and a few nits.
2891 Revision 1.61.2.30 2003/06/25 01:13:52 hal9
2894 - FAQ on "Unable to get my own hostname"
2895 - Another one on filtering effects on text files.
2897 Revision 1.61.2.29 2003/06/15 21:32:58 hal9
2898 Add to the 4.17 (filtering effects on downloaded files).
2900 Revision 1.61.2.28 2003/03/18 19:37:21 oes
2901 s/Advanced|Radical/Adventuresome/g to avoid complaints re fun filter
2903 Revision 1.61.2.27 2002/12/01 06:31:58 hal9
2904 Add faq on win32 error 503 due to ZoneAlarm.
2906 Revision 1.61.2.26 2002/11/17 06:41:06 hal9
2907 Move default profiles table from FAQ to U-M, and other minor related changes.
2910 Revision 1.61.2.25 2002/10/29 03:21:50 hal9
2911 Add 3 Q/A's relating to HTML in email. Other minor touchups.
2913 Revision 1.61.2.24 2002/10/15 12:50:22 oes
2914 s/Advanced/Radical/ (stupid me)
2916 Revision 1.61.2.23 2002/10/15 12:38:56 oes
2917 Added Microsuck faq; more detail for PHP problem
2919 Revision 1.61.2.22 2002/10/12 01:13:13 hal9
2920 Updates for demoronizer, more commentary on Radical profile, and update on
2921 the srvany.exe/icon fix.
2923 Revision 1.61.2.21 2002/10/10 04:09:35 hal9
2924 s/Advanced/Radical/ and added very brief note.
2926 Revision 1.61.2.20 2002/09/26 01:22:45 hal9
2927 Small additions for LAN setup, content-cookies/SSL, and FTP non-support.
2929 Revision 1.61.2.19 2002/08/25 23:31:56 hal9
2930 Fix one grammatical error. Add brief FAQ relating to tranparent proxies (ie
2931 port 80 setting). Add FAQ on effects of Privoxy on downloaded files
2932 (especially filtering).
2934 Revision 1.61.2.18 2002/08/14 16:39:37 hal9
2935 Fix wrong tag on FAQ addition.
2937 Revision 1.61.2.17 2002/08/14 00:01:18 hal9
2940 Revision 1.61.2.16 2002/08/13 00:10:38 hal9
2941 Add faq to troubleshooting re: blank page syndrome, ie {-prevent-compression}.
2943 Revision 1.61.2.15 2002/08/10 11:34:22 oes
2944 Add disclaimer about probably being out-of-date
2946 Revision 1.61.2.14 2002/08/07 02:53:43 hal9
2947 Fix some minor markup errors, and move one OSX Q/A to troubleshooting section.
2949 Revision 1.61.2.13 2002/08/06 11:55:32 oes
2950 Added missing close tag
2952 Revision 1.61.2.12 2002/08/06 11:43:46 david__schmidt
2953 Updated OSX uninstall FAQ... we have an uninstall script now.
2955 Revision 1.61.2.11 2002/08/06 08:54:03 oes
2956 Style police: Fixed formatting details
2958 Revision 1.61.2.10 2002/08/02 14:00:25 david__schmidt
2959 Made the OSX removal commands far less dangerous
2961 Revision 1.61.2.9 2002/08/02 13:14:45 oes
2962 Added warning about sudo rm -r for Mac OSX deinstallation; moved this item to install section
2964 Revision 1.61.2.8 2002/08/02 02:01:42 david__schmidt
2965 Add FAQ item for MSIE on OSX HTTP proxy confusion
2967 Revision 1.61.2.7 2002/08/02 01:46:01 david__schmidt
2968 Added FAQ item for Mac OSX uninstall woes
2970 Revision 1.61.2.6 2002/07/30 20:04:56 hal9
2971 Fix typo: 'schould'.
2973 Revision 1.61.2.5 2002/07/26 15:22:58 oes
2974 - Updated to reflect changes in standard.action
2975 - Added info on where to get updated actions files
2977 Revision 1.61.2.4 2002/07/25 21:42:29 hal9
2978 Add brief notes on not proxying non-HTTP protocols.
2980 Revision 1.61.2.3 2002/06/09 16:36:33 hal9
2981 Clarifications on filtering and MIME. Hardcode 'latest release' in index.html.
2983 Revision 1.61.2.2 2002/06/06 02:51:34 hal9
2984 Fix typo in URL http:/config.privoxy.org
2986 Revision 1.61.2.1 2002/06/05 23:10:43 hal9
2987 Add new FAQ re: DUN/IE. Change release date from May to June :)
2989 Revision 1.61 2002/05/25 12:37:25 hal9
2990 Various minor changes and edits.
2992 Revision 1.60 2002/05/22 17:17:48 oes
2993 Proofread & added more links into u-m
2995 Revision 1.59 2002/05/15 04:03:30 hal9
2996 Fix ulink -> link markup.
2998 Revision 1.58 2002/05/10 01:48:20 hal9
2999 This is mostly proposed copyright/licensing additions and changes. Docs
3000 are still GPL, but licensing and copyright are more visible. Also, copyright
3001 changed in doc header comments (eliminate references to JB except FAQ).
3003 Revision 1.57 2002/05/05 20:26:02 hal9
3004 Sorting out license vs copyright in these docs.
3006 Revision 1.56 2002/05/04 08:44:44 swa
3009 Revision 1.55 2002/05/04 00:41:56 hal9
3010 -Remove TOC/first page kludge in favor of proper handling via dsl file.
3012 Revision 1.54 2002/05/03 05:06:44 hal9
3013 Add brief Q/A on transparent proxies.
3015 Revision 1.53 2002/05/03 01:34:52 hal9
3016 Fix section numbering for new sections (due to TOC kludge).
3018 Revision 1.52 2002/04/29 03:08:43 hal9
3019 -Added new Q/A on new actions file set up (pointer to u-m)
3020 -Fixed a few broken links and converted old actions as a result of
3023 Revision 1.51 2002/04/26 17:24:31 swa
3024 bookmarks cleaned, changed structure of user manual, screen and programlisting cleanups, and numerous other changes that I forgot
3026 Revision 1.50 2002/04/26 05:25:23 hal9
3027 Mass commit to catch a few scattered fixes.
3029 Revision 1.49 2002/04/12 10:10:18 swa
3032 Revision 1.48 2002/04/10 18:45:15 swa
3035 Revision 1.47 2002/04/10 04:05:32 hal9
3038 Revision 1.45 2002/04/08 22:59:26 hal9
3039 Version update. Spell chkconfig correctly :)
3041 Revision 1.44 2002/04/07 21:24:29 hal9
3042 Touch up on name change.
3044 Revision 1.43 2002/04/04 21:59:53 hal9
3045 Added NT/W2K service/icon situation.
3047 Revision 1.42 2002/04/04 18:46:47 swa
3048 consistent look. reuse of copyright, history et. al.
3050 Revision 1.41 2002/04/04 06:48:37 hal9
3051 Structural changes to allow for conditional inclusion/exclusion of content
3052 based on entity toggles, e.g. 'entity % p-not-stable "INCLUDE"'. And
3053 definition of internal entities, e.g. 'entity p-version "2.9.13"' that will
3054 eventually be set by Makefile.
3055 More boilerplate text for use across multiple docs.
3057 Revision 1.40 2002/04/03 04:22:03 hal9
3058 Fixed several typos.
3060 Revision 1.39 2002/04/03 03:53:03 hal9
3061 Revert some changes, and then make some news, to layout, and appearance.
3063 Revision 1.38 2002/04/02 03:49:10 hal9
3064 Major changes to doc structure and layout. Sections are not automatically
3065 numbered now. TOC is on page by itself.
3067 Revision 1.37 2002/04/01 16:24:07 hal9
3068 -Rework of supported Q/A.
3069 -Set up entities to include boilerplate text.
3071 Revision 1.36 2002/03/31 23:18:47 hal9
3072 More on dealing with BLOCKED.
3074 Revision 1.35 2002/03/30 04:14:19 hal9
3075 Fix privoxy.org/config links.
3077 Revision 1.34 2002/03/29 04:35:56 hal9
3080 Revision 1.33 2002/03/29 01:31:48 hal9
3081 Several new Q/A's and other touch ups.
3083 Revision 1.32 2002/03/27 00:57:03 hal9
3084 Touch ups for name change.
3086 Revision 1.31 2002/03/26 22:29:55 swa
3087 we have a new homepage!
3089 Revision 1.30 2002/03/25 16:39:22 hal9
3090 A few new sections. Made all links relative to user-manual.
3092 Revision 1.29 2002/03/25 05:23:57 hal9
3093 Moved section, and touch ups.
3095 Revision 1.28 2002/03/25 04:27:33 hal9
3096 New section related to name change.
3098 Revision 1.25 2002/03/24 16:08:08 swa
3099 we are too lazy to make a block-built
3100 privoxy logo. hence removed the option.
3102 Revision 1.24 2002/03/24 15:46:20 swa
3103 name change related issue.
3105 Revision 1.23 2002/03/24 12:33:01 swa
3108 Revision 1.22 2002/03/24 11:51:00 swa
3109 name change. changed filenames.
3111 Revision 1.21 2002/03/24 11:01:06 swa
3114 Revision 1.20 2002/03/23 15:13:11 swa
3115 renamed every reference to the old name with foobar.
3116 fixed "application foobar application" tag, fixed
3117 "the foobar" with "foobar". left junkbustser in cvs
3118 comments and remarks to history untouched.
3120 Revision 1.19 2002/03/21 17:01:54 hal9
3123 Revision 1.18 2002/03/18 16:40:31 hal9
3126 Revision 1.17 2002/03/18 03:53:53 hal9
3129 Revision 1.16 2002/03/17 21:32:56 hal9
3130 A few more additions.
3132 Revision 1.15 2002/03/17 07:25:59 hal9
3133 Correcting some of my typos, and some additions.
3135 Revision 1.14 2002/03/17 02:39:13 hal9
3136 A little more added ...
3138 Revision 1.13 2002/03/17 00:22:20 hal9
3139 Adding new stuff, and trying to incorporate stuff from old faq.
3141 Revision 1.12 2002/03/11 20:13:21 swa
3144 Revision 1.11 2002/03/11 18:42:27 swa
3147 Revision 1.10 2002/03/11 13:13:27 swa
3148 correct feedback channels
3150 Revision 1.9 2002/03/10 23:34:04 swa
3151 more info on not hiding ip address
3153 Revision 1.8 2002/03/09 15:55:48 swa
3154 added default config section
3156 Revision 1.7 2002/03/07 18:16:55 swa
3159 Revision 1.6 2002/03/07 13:16:31 oes
3160 Committing changes by Stefan
3162 Revision 1.5 2002/03/02 15:50:04 swa
3163 2.9.11 version. more input for docs.
3165 Revision 1.4 2002/02/24 14:34:24 jongfoster
3166 Formatting changes. Now changing the doctype to DocBook XML 4.1
3167 will work - no other changes are needed.
3169 Revision 1.3 2001/09/23 10:13:48 swa
3170 upload process established. run make webserver and
3171 the documentation is moved to the webserver. documents
3172 are now linked correctly.
3174 Revision 1.2 2001/09/13 15:20:17 swa
3175 merged standards into developer manual
3177 Revision 1.1 2001/09/12 15:36:41 swa
3178 source files for junkbuster documentation
3180 Revision 1.3 2001/09/10 17:43:59 swa
3181 first proposal of a structure.
3183 Revision 1.2 2001/06/13 14:28:31 swa
3184 docs should have an author.
3186 Revision 1.1 2001/06/13 14:20:37 swa
3187 first import of project's documentation for the webserver.