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 "3.0.22">
12 <!entity p-status "UNRELEASED">
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 % seealso-extra "INCLUDE"> <!-- extra stuff from seealso.sgml -->
21 <!entity my-app "<application>Privoxy</application>">
24 File : $Source: /cvsroot/ijbswa/current/doc/source/faq.sgml,v $
27 This file belongs into
28 ijbswa.sourceforge.net:/home/groups/i/ij/ijbswa/htdocs/
30 $Id: faq.sgml,v 2.105 2014/11/28 14:26:35 fabiankeil Exp $
32 Copyright (C) 2001-2014 Privoxy Developers http://www.privoxy.org/
35 Based partially on the Internet Junkbuster FAQ originally written by and
36 Copyright (C) 1997 Anonymous Coders and Junkbusters Corporation.
37 http://www.junkbusters.com/
39 <Qandaset defaultlabel='qanda'>
54 ========================================================================
55 NOTE: Please read developer-manual/documentation.html before touching
58 Please we keep the info in this file as version independent as possible
59 so we only have to maintain one FAQ. Where significant changes are
60 made to Privoxy configuration, please note the change in such a way that
61 it makes sense to both users of older and newer versions.
62 ========================================================================
68 <article id="index" class="faq">
70 <title>Privoxy Frequently Asked Questions</title>
74 <!-- Completely the wrong markup, but very little is allowed -->
75 <!-- in this part of an article. FIXME -->
76 <link linkend="copyright">Copyright</link> &my-copy; 2001-2014 by
77 <ulink url="http://www.privoxy.org/">Privoxy Developers</ulink>
81 <pubdate>$Id: faq.sgml,v 2.105 2014/11/28 14:26:35 fabiankeil Exp $</pubdate>
85 Note: this should generate a separate page, and a live link to it.
86 But it doesn't for some mysterious reason. Please leave commented
87 unless it can be fixed proper. For the time being, the copyright
88 statement will be in copyright.smgl.
92 <legalnotice id="legalnotice">
94 text goes here ........
104 <orgname>By: Privoxy Developers</orgname>
113 This is here to keep vim syntax file from breaking :/
114 If I knew enough to fix it, I would.
115 PLEASE DO NOT REMOVE! HB: hal@foobox.net
120 This FAQ gives quick answers to frequently asked questions about
121 <ulink url="http://www.privoxy.org/">Privoxy</ulink>.
122 It is not a substitute for the
123 <ulink url="../user-manual/index.html"><citetitle>Privoxy User Manual</citetitle></ulink>.
125 This works, at least in some situtations:
126 Test: <ulink url="privoxy-user-manual.pdf"><citetitle>User Manual</citetitle></ulink>.
130 <!-- Include privoxy.sgml boilerplate: -->
131 <para>What is Privoxy?</para> &p-intro;
132 <!-- end boilerplate -->
135 Please note that this document is a work in progress. This copy represents
136 the state at the release of version &p-version;.
137 You can find the latest version of the document at <ulink
138 url="http://www.privoxy.org/faq/">http://www.privoxy.org/faq/</ulink>.
139 Please see the <link linkend="contact">Contact section</link> if you want to
140 contact the developers.
144 <!-- Feel free to send a note to the developers at <email>ijbswa-developers@lists.sourceforge.net</email>. -->
150 <!-- ~~~~~ New section ~~~~~ -->
152 <sect1 id="general"><title>General Information</title>
153 <sect2 renderas="sect3" id="who-uses"><title>Who should give &my-app; a try?</title>
155 Anyone who is interested in security, privacy, or in
156 finer-grained control over their web and Internet experience.
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 with the willingness to read the documentation
165 and the ability to fine-tune their installation will benefit the most.
168 One of <application>Privoxy's</application>
169 strengths is that it is highly configurable giving you the ability to
170 completely personalize your installation. Being familiar with, or at least
171 having an interest in learning about <ulink
172 url="http://en.wikipedia.org/wiki/Http">HTTP</ulink> and other networking
173 protocols, <ulink url="http://en.wikipedia.org/wiki/Html">HTML</ulink>, and
174 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
175 Expressions</quote></ulink>
176 will be a big plus and will help you get the most out of &my-app;.
177 A new installation just includes a very basic configuration. The user
178 should take this as a starting point only, and enhance it as he or she
179 sees fit. In fact, the user is encouraged, and expected to, fine-tune the
183 Much of <application>Privoxy's</application> configuration can be done
184 with a <ulink url="http://en.wikipedia.org/wiki/Web_browser">Web browser</ulink>.
185 But there are areas where configuration is done using a
186 <ulink url="http://en.wikipedia.org/wiki/Text_editors">text editor</ulink>
187 to edit configuration files. Also note that the web-based action editor
188 doesn't use authentication and should only be enabled in environments
189 where all clients with access to &my-app; listening port can be trusted.
193 <sect2 renderas="sect3" id="proxymoron"><title>What is a <quote>proxy</quote>? How does
194 Privoxy work? </title>
196 A <ulink url="http://en.wikipedia.org/wiki/Proxy_server">web proxy</ulink>
197 is a service, based on a software such as &my-app;, that clients
198 (i.e. browsers) can use instead of connecting to web servers directly.
199 The clients then ask the proxy to request objects (web pages, images, movies etc)
200 on their behalf and to forward the data to the clients.
201 It is a <quote>go-between</quote>. For details, see
202 <ulink url="http://en.wikipedia.org/wiki/Proxy_server">Wikipedia's proxy definition</ulink>.
205 There are many reasons to use web proxies, such as security (firewalling),
206 efficiency (caching) and others, and there are any number of proxies
207 to accommodate those needs.
210 &my-app; is a proxy that is primarily focused on
211 privacy enhancement, ad and junk elimination and freeing the user from
212 restrictions placed on his activities. Sitting between your browser(s) and the Internet,
213 it is in a perfect position to filter outbound personal information that your
214 browser is leaking, as well as inbound junk. It uses a variety of techniques to do
215 this, all of which are under your complete control via the various configuration
216 files and options. Being a proxy also makes it easier to share
217 configurations among multiple browsers and/or users.
221 <sect2 renderas="sect3" id="otherstuff">
222 <title>Does Privoxy do anything more than ad blocking?</title>
224 Yes, ad blocking is but one possible use. There are many, many ways &my-app;
225 can be used to sanitize and customize web browsing.
229 <sect2 renderas="sect3" id="newjb"><title>What is this new version of
230 <quote><citetitle>Junkbuster</citetitle></quote>?</title>
232 <!-- Include history.sgml -->
239 <sect2 renderas="sect3">
240 <title id="whyprivoxy">Why <quote>Privoxy</quote>? Why change the name from
241 Junkbuster at all?</title>
243 Though outdated, Junkbusters Corporation continued to offer their original
244 version of the <application>Internet Junkbuster</application> for a while,
245 so publishing our <application> Junkbuster</application>-derived software
246 under the same name would have led to confusion.
249 There were also potential legal reasons not to use the
250 <application>Junkbuster</application> name, as it was (and maybe still is)
251 a registered trademark of Junkbusters Corporation.
252 There were, however, no objections from Junkbusters Corporation to the
253 <application>Privoxy</application> project itself, and they, in fact,
254 shared our ideals and goals.
257 The Privoxy developers also believed that there were so many improvements
258 over the original code, that it was time to make a clean break from the past
259 and make 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.
275 <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, most of these features have been enhanced,
279 and many new ones 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 That depends on your expectations.
346 The default installation should give you a good starting
347 point, and block <emphasis>most</emphasis> ads and unwanted content,
348 but many of the more advanced features are off by default, and require
349 you to activate them.
352 You do have to set up your browser to use
353 <application>Privoxy</application> (see the <link
354 linkend="firststep">Installation section below</link>).
357 And you will certainly run into situations where there are false positives,
358 or ads not being blocked that you may not want to see. In these cases, you
359 would certainly benefit by customizing <application>Privoxy's</application>
360 configuration to more closely match your individual situation. And we
361 encourage you to do this. This is where the real power of
362 <application>Privoxy</application> lies!
367 <sect2 renderas="sect3" id="lan">
368 <title>Can Privoxy run as a server on a network?</title>
370 Yes, &my-app; runs as a server already, and can easily be configured to
371 <quote>serve</quote> more than one client. See <link linkend="lanconfig">
372 How can I set up Privoxy to act as a proxy for my LAN</link> below.
376 <sect2 renderas="sect3" id="browsers2"><title>My browser does the same things as
377 Privoxy. Why should I use Privoxy at all?</title>
379 Modern browsers do indeed have <emphasis>some</emphasis> of the same
380 functionality as <application>Privoxy</application>. Maybe this is
381 adequate for you. But <application>Privoxy</application> is very
382 versatile and powerful, and can probably do a number of things
383 your browser just can't.
386 In addition, a proxy is good choice if you use multiple browsers, or
387 have a LAN with multiple computers since &my-app; can run as a server
388 application. This way all the configuration is in one place, and you don't
389 have to maintain a similar configuration for possibly many browsers or
393 Note, however, that it's recommended to leverage both your browser's
394 and <application>Privoxy's</application> privacy enhancing features
395 at the same time. While your browser probably lacks some features
396 &my-app; offers, it should also be able to do some things more
397 reliably, for example restricting and suppressing JavaScript.
401 <sect2 renderas="sect3" id="whytrust"><title>Why should I trust Privoxy?</title>
403 The most important reason is because you have access to
404 <emphasis>everything</emphasis>, and you can control everything. You can
405 check every line of every configuration file yourself. You can check every
406 last bit of source code should you desire. And even if you can't read code,
407 there should be some comfort in knowing that <!-- thousands of -->other people can,
408 and do read it. You can build the software from scratch, if you want,
409 so that you know the executable is clean, and that it is
410 <emphasis>yours</emphasis>. In fact, we encourage this level of scrutiny. It
411 is one reason we use &my-app; ourselves.
415 <sect2 renderas="sect3" id="license"><title>Is there is a license or fee? What about a
416 warranty? Registration?</title>
418 <application>Privoxy</application> is free software and licensed under the <ulink
419 url="http://www.gnu.org/licenses/old-licenses/gpl-2.0.html">GNU General Public License (GPL) version 2</ulink>.
420 It is free to use, copy, modify or distribute as you wish under the terms of this
421 license. Please see the <link linkend="copyright">Copyright</link> section for more
422 information on the license and copyright. Or the <filename>LICENSE</filename> file
423 that should be included.
426 There is <emphasis>no warranty</emphasis> of any kind, expressed, implied or otherwise.
427 That is something that would cost real money ;-) There is no registration either.
432 <sect2 renderas="sect3" id="spyware">
433 <title>Can Privoxy remove spyware? Adware? Viruses?</title>
435 No, at least not reliably enough to trust it. &my-app; is not designed to be
436 a malware removal tool and the default configuration doesn't even try to
437 filter out any malware.
440 &my-app; could help prevent contact from (known) sites that use such
441 tactics with appropriate configuration rules, and thus could conceivably
442 prevent contamination from such sites. However, keeping such a configuration
443 up to date would require a lot of time and effort that would be better spend
444 on keeping your software itself up to date so it doesn't have known
450 <sect2 renderas="sect3" id="otherads">
451 <title>Can I use Privoxy with other ad-blocking software?</title>
453 &my-app; should work fine with other proxies and other software in general.
456 But it is probably not necessary to use &my-app; in conjunction with other
457 ad-blocking products, and this could conceivably cause undesirable results.
458 It might be better to choose one software or the other and work a little to
459 tweak its configuration to your liking.
462 Note that this is an advice specific to ad blocking.
466 <sect2 renderas="sect3" id="help-the-developers"><title id="jointeam">I would like to help you, what can I do?</title>
468 <sect3 renderas="sect4" id="participate"><title id="jointeam-work">Would you like to participate?</title>
470 Well, we <emphasis>always</emphasis> need help. There is something for
471 everybody who wants to help us. We welcome new developers, packagers,
472 testers, documentation writers or really anyone with a desire to help in
473 any way. You <emphasis>DO NOT</emphasis> need to be a
474 <quote>programmer</quote>. There are many other tasks available. In fact,
475 the programmers often can't spend as much time programming because of some
476 of the other, more mundane things that need to be done, like checking the
477 Tracker feedback sections or responding to user questions on the mailing
481 So first thing, subscribe to the <ulink
482 url="https://lists.sourceforge.net/lists/listinfo/ijbswa-users">Privoxy Users</ulink>
483 or the <ulink url="https://lists.sourceforge.net/lists/listinfo/ijbswa-developers">Privoxy
484 Developers</ulink> mailing list, join the discussion, help out other users, provide general
485 feedback or report problems you noticed.
488 If you intend to help out with the trackers, you also might want to <ulink
489 url="https://sourceforge.net/user/registration">get an account on SourceForge.net</ulink>
490 so we don't confuse you with the other name-less users.
493 We also have a <ulink
494 url="../developer-manual/index.html">Developer's Manual</ulink>.
495 While it is partly out of date, it's still worth reading.
498 Our <ulink url="http://ijbswa.cvs.sourceforge.net/viewvc/ijbswa/current/TODO?view=markup">TODO list</ulink>
499 may be of interest to you as well.
500 Please let us know if you want to work on one of the items listed.
504 <sect3 renderas="sect4" id="donate"><title>Would you like to donate?</title>
506 Donations are welcome. Our
507 <ulink url="http://ijbswa.cvs.sourceforge.net/viewvc/ijbswa/current/TODO">TODO list</ulink>
508 is rather long and being able to pay one (or more) developers to work on Privoxy
509 would make a huge difference, even if it was only for a couple of weeks. Donations may
510 also be used for Privoxy-related travel expenses (for example to attend conferences),
511 for hardware used for Privoxy development and for hosting expenses etc.
515 <application>Privoxy</application> is an associated
516 project of <ulink url="http://www.spi-inc.org/">Software
517 in the Public Interest (SPI)</ulink>, which allows us to receive
518 tax-deductible donations in the United States. If you want to donate through
519 SPI, please use <ulink url="http://www.spi-inc.org/donations">SPI's donation page</ulink>
520 to see what the options are.
524 You can also donate to Privoxy using a bank account managed by
525 <ulink url="https://www.zwiebelfreunde.de/">Zwiebelfreunde e.V.</ulink>:
528 Name on Account: Zwiebelfreunde e.V.
529 IBAN: DE95430609671126825604
534 Donations made through Zwiebelfreunde e.V. are tax-deductible in Germany
535 and other countries that recognize German charitable clubs. Feel free to
536 use the Subject field to provide a name to be credited and a list of TODO
537 list items you are interested in the most. For example: Max Mustermann: #16, #1, #14.
541 If you have any questions regarding donations please mail to either the
542 public user mailing list or, if it's a private matter, to
543 <ulink url="mailto:fk@fabiankeil.de">Fabian Keil</ulink> (Privoxy's SPI liason)
552 <!-- ~~~~~ New section ~~~~~ -->
554 <sect1 id="installation"><title>Installation</title>
556 <sect2 renderas="sect3" id="whichbrowsers">
557 <title>Which browsers are supported by Privoxy?</title>
559 Any browser that can be configured to use a proxy, which
560 should be virtually all browsers, including
561 <application>Firefox</application>, <application>Internet
562 Explorer</application>, <application>Opera</application>, and
563 <application>Safari</application> among others.
564 Direct browser support is not an absolute requirement since
565 <application>Privoxy</application> runs as a separate application and talks
566 to the browser in the standardized HTTP protocol, just like a web server
571 <sect2 renderas="sect3" id="whichos">
572 <title>Which operating systems are supported?</title>
574 Include supported.sgml here:
579 <sect2 renderas="sect3" id="email-client">
580 <title>Can I use Privoxy with my email client?</title>
582 As long as there is some way to set a HTTP proxy for the client, then yes,
583 any application can be used, whether it is strictly speaking a
584 <quote>browser</quote> or not. Though this may not be the best approach for
585 dealing with some of the common abuses of HTML in email. See <link
586 linkend="outlook">How can I configure <application>Privoxy</application>
587 with <application>Outlook</application>?</link> below for more on
591 Be aware that HTML email presents a number of unique security and privacy
592 related issues, that can require advanced skills to overcome. The developers
593 recommend using email clients that can be configured to convert HTML to plain
594 text for these reasons.
598 <!-- Nobody is going to still be doing this!
599 <sect2 renderas="sect3" id="newinstall"><title>Can I install
600 Privoxy over Junkbuster?</title>
602 We recommend you un-install <application>Junkbuster</application>
603 first to minimize conflicts and confusion. You may want to
604 save your old configuration files for future reference. The configuration
605 files and syntax have substantially changed, so you will need to manually
606 port your old patterns. See the <ulink url="../user-manual/upgradersnote.html">note
607 to upgraders</ulink> and <ulink url="../user-manual/installation.html">installation
608 chapter</ulink> in the <ulink url="../user-manual/index.html">User Manual</ulink>
612 Note: Some installers may automatically un-install
613 <application>Junkbuster</application>, if present!
619 <sect2 renderas="sect3" id="firststep">
620 <title>I just installed Privoxy. Is there anything
621 special I have to do now?</title>
624 All browsers should be told to use <application>Privoxy</application>
625 as a proxy by specifying the correct proxy address and port number
626 in the appropriate configuration area for the browser. It's possible
627 to combine &my-app; with a packet filter to intercept HTTP requests
628 even if the client isn't explicitly configured to use &my-app;,
629 but where possible, configuring the client is recommended. See
630 <ulink url="../user-manual/startup.html">the User Manual for more
631 details</ulink>. You should also flush your browser's memory and disk
632 cache to get rid of any cached junk items, and remove any stored
633 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>.
639 <sect2 renderas="sect3" id="localhost"><title>What is the proxy address of Privoxy?</title>
641 If you set up the <application>Privoxy</application> to run on
642 the computer you browse from (rather than your ISP's server or some
643 networked computer on a LAN), the proxy will be on <literal>127.0.0.1</literal>
644 (sometimes referred to as <quote>localhost</quote>,
645 which is the special name used by every computer on the Internet to refer
646 to itself) and the port will be 8118 (unless you used the <ulink
647 url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink>
648 config option to tell <application>Privoxy</application> to run on
652 When configuring your browser's proxy settings you typically enter
653 the word <quote>localhost</quote> or the IP address <quote>127.0.0.1</quote>
654 in the boxes next to <quote>HTTP</quote> and <quote>Secure</quote> (HTTPS) and
655 then the number <quote>8118</quote> for <quote>port</quote>.
656 This tells your browser to send all web requests to <application>Privoxy</application>
657 instead of directly to the Internet.
660 <application>Privoxy</application> can also be used to proxy for
661 a Local Area Network. In this case, your would enter either the IP
662 address of the LAN host where <application>Privoxy</application>
663 is running, or the equivalent hostname, e.g. <literal>192.168.1.1</literal>.
664 Port assignment would be same as above. Note that
665 <application>Privoxy</application> doesn't listen on any LAN interfaces by
669 <application>Privoxy</application> does not currently handle
670 any other protocols such as FTP, SMTP, IM, IRC, ICQ, etc.
674 <sect2 renderas="sect3" id="nothing">
675 <title>I just installed Privoxy, and nothing is happening.
676 All the ads are there. What's wrong?</title>
679 Did you configure your browser to use <application>Privoxy</application>
680 as a proxy? It does not sound like it. See above. You might also try flushing
681 the browser's caches to force a full re-reading of pages. You can verify
682 that <application>Privoxy</application> is running, and your browser
683 is correctly configured by entering the special URL:
684 <ulink url="http://p.p/">http://p.p/</ulink>.
685 <!-- Use http://p.p/ instead of http://config.privoxy.org/ here because
686 of potential redirect caching problem (see next Q). -->
687 This should take you to a page titled <quote>This is Privoxy..</quote> with
688 access to <application>Privoxy's</application> internal configuration.
689 If you see this, then you are good to go. If you receive a page saying
690 <quote>Privoxy is not running</quote>, then the browser is not set up to use
691 your <application>Privoxy</application> installation.
692 If you receive anything else (probably nothing at all), it could either
693 be that the browser is not set up correctly, or that
694 <application>Privoxy</application> is not running at all. Check the <ulink
695 url="../user-manual/config.html#LOGFILE">log file</ulink>. For instructions
696 on starting <application>Privoxy</application> and browser configuration,
697 see the <ulink url="http://www.privoxy.org/user-manual/startup.html">chapter
698 on starting <application>Privoxy</application></ulink> in the
699 <ulink url="http://www.privoxy.org/user-manual/">User Manual</ulink>.
704 <sect2 renderas="sect3" id="notused">
705 <title>I get a <quote>Privoxy is not being used</quote> dummy page although
706 Privoxy is running and being used.</title>
709 First, make sure that Privoxy is <emphasis>really</emphasis> running and
710 being used by visiting <ulink url="http://p.p/">http://p.p/</ulink>. You
711 should see the <application>Privoxy</application> main page. If not, see
712 the <ulink url="http://www.privoxy.org/user-manual/startup.html">chapter
713 on starting <application>Privoxy</application></ulink> in the
714 <ulink url="http://www.privoxy.org/user-manual/">User Manual</ulink>.
718 Now if <ulink url="http://p.p/">http://p.p/</ulink> works for you, but
719 other parts of <application>Privoxy</application>'s web interface show
720 the dummy page, your browser has cached a redirection it encountered before
721 <application>Privoxy</application> was being used. You need to clear your
722 browser's cache. Note that shift-reloading the dummy page won't help, since
723 that'll only refresh the dummy page, not the redirection that lead you there.
727 The procedure for clearing the cache varies from browser to browser. For
728 example, <application>Mozilla/Netscape</application> users would click
729 <guibutton>Edit</guibutton> --> <guibutton>Preferences</guibutton> -->
730 <guibutton>Advanced</guibutton> --> <guibutton>Cache</guibutton> and
731 then click both <quote><guibutton>Clear Memory Cache</guibutton></quote>
732 and <quote><guibutton>Clear Disk Cache</guibutton></quote>.
733 In some <application>Firefox</application> versions it's
734 <guibutton>Tools</guibutton> --> <guibutton>Options</guibutton> -->
735 <guibutton>Privacy</guibutton> --> <guibutton>Cache</guibutton> and
736 then click <quote><guibutton>Clear Cache Now</guibutton></quote>.
737 <!-- In my Firefox versions it's the Netscape way. fk 2007-11-19-->
744 <!-- ~~~~~ New section ~~~~~ -->
746 <sect1 id="configuration"><title>Configuration</title>
747 <sect2 renderas="sect3">
748 <title id="actionsfile">What exactly is an <quote>actions</quote> file?</title>
751 &my-app; utilizes the concept of <quote>
752 <ulink url="../user-manual/actions-file.html#ACTIONS">actions</ulink></quote>
753 that are used to manipulate and control web page data.
754 <ulink url="../user-manual/actions-file.html">Actions files</ulink>
755 are where these <ulink url="../user-manual/actions-file.html#ACTIONS">actions</ulink>
756 that <application>Privoxy</application> could take while processing a certain
757 request, are configured. Typically, you would define a set of default actions
758 that apply globally to all URLs, then add exceptions to these defaults where needed.
759 There is a wide array of actions available that give the user a high degree
760 of control and flexibility on how to process each and every web page.
764 Actions can be defined on a <ulink
765 url="../user-manual/actions-file.html#AF-PATTERNS">URL pattern</ulink> basis, i.e.
766 for single URLs, whole web sites, groups or parts thereof etc. Actions can also be
767 grouped together and then applied to requests matching one or more patterns.
768 There are many possible actions that might apply to any given site. As an example,
769 if you are blocking <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>
770 as one of your default actions, but need to accept cookies from a given site,
771 you would need to define an exception for this site in one of your actions
772 files, preferably in <filename>user.action</filename>.
777 <sect2 renderas="sect3" id="actionss">
778 <title>The <quote>actions</quote> concept confuses me. Please list
779 some of these <quote>actions</quote>.</title>
781 For a comprehensive discussion of the actions concept, please refer
782 to the <ulink url="../user-manual/actions-file.html">actions file
783 chapter</ulink> in the <ulink url="../user-manual/index.html">User
784 Manual</ulink>. It includes a <ulink
785 url="../user-manual/actions-file.html#ACTIONS">list of all actions</ulink>
786 and an <ulink url="../user-manual/actions-file.html#ACT-EXAMPLES">actions
787 file tutorial</ulink> to get you started.
792 <sect2 renderas="sect3">
793 <title id="actconfig">How are actions files configured? What is the easiest
794 way to do this?</title>
797 Actions files are just text files in a special syntax and can be edited
798 with a text editor. But probably the easiest way is to access
799 <application>Privoxy</application>'s user interface with your web browser
800 at <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
801 (Shortcut: <ulink url="http://p.p/">http://p.p/</ulink>) and then select
802 <quote><ulink url="http://config.privoxy.org/show-status">View &
803 change the current configuration</ulink></quote> from the menu. Note
804 that this feature must be explicitly enabled in the main config file
806 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>).
811 <sect2 renderas="sect3">
812 <title>There are several different <quote>actions</quote> files. What are
813 the differences?</title>
815 Please have a look at the <ulink url="../user-manual/actions-file.html">the actions chapter</ulink>
816 in the <ulink url="../user-manual/index.html">User Manual</ulink> for a detailed explanation.
821 <sect2 renderas="sect3" id="getupdates"><title>Where can I get updated Actions Files?</title>
823 Based on your feedback and the continuing development, updates of
824 <filename>default.action</filename> will be
825 made available from time to time on the <ulink
826 url="http://sourceforge.net/project/showfiles.php?group_id=11118">files section</ulink> of
827 our <ulink url="http://sf.net/projects/ijbswa/">project page</ulink>.
831 If you wish to receive an email notification whenever we release updates of
832 <application>Privoxy</application> or the actions file, <ulink
833 url="http://lists.sourceforge.net/lists/listinfo/ijbswa-announce/">subscribe
834 to our announce mailing list</ulink>, ijbswa-announce@lists.sourceforge.net.
839 <sect2 renderas="sect3" id="newconfig"><title>Can I use my old config files?</title>
841 The syntax and purpose of configuration files has remained roughly the
842 same throughout the 3.x series, but backwards compatibility is not guaranteed.
843 Also each release contains updated, <quote>improved</quote> versions and it is
844 therefore strongly recommended to install the newer configuration files
845 and merge back your modifications.
849 <sect2 renderas="sect3" id="difficult">
850 <title>Why is the configuration so complicated?</title>
852 <quote>Complicated</quote> is in the eye of the beholder.
855 Privoxy is currently mainly written by and for people who are already
856 familiar with the underlying concepts like regular expressions, HTTP and HTML,
857 or are willing to become familiar with them to be able to get the most
858 out of a powerful and flexible tool such as Privoxy.
861 While everybody is expected to be able to get a Privoxy default installation
862 up and running, fine-tuning requires a certain amount of background
863 information and Privoxy's documentation mainly concentrates on the
864 Privoxy-specific parts while only providing references to the rest.
867 If you or anyone you know has the skills, time and energy to
868 reduce the barrier of entry, please <link linkend="participate">get involved</link>.
872 <sect2 renderas="sect3" id="yahoo"><title>How can I make my Yahoo/Hotmail/Gmail account work?</title>
874 The default configuration shouldn't impact the usability of any of these services.
875 It may, however, make all <ulink
876 url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>
877 temporary, so that your browser will forget your
878 login credentials in between browser sessions. If you would like not to have to log
879 in manually each time you access those websites, simply turn off all cookie handling
880 for them in the <filename>user.action</filename> file. An example for yahoo might
884 <screen># Allow all cookies for Yahoo login:
886 { -<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> }
887 .login.yahoo.com</screen>
890 These kinds of sites are often quite complex and heavy with
891 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink> and
892 thus <quote>fragile</quote>. So if <emphasis>still</emphasis> a problem,
894 url="../user-manual/actions-file.html#ALIASES">alias</ulink> just for such
898 <screen># Gmail is a _fragile_ site:
900 { <literal>fragile</literal> }
902 mail.google.com</screen>
905 Be sure to flush your browser's caches whenever making these kinds of
906 changes, just to make sure the changes <quote>take</quote>.
909 Make sure the domain, host and path are appropriate as well. Your browser can
910 tell you where you are specifically and you should use that information for
911 your configuration settings. Note that above it is not referenced as
912 <literal>gmail.com</literal>, which is a valid domain name.
917 <sect2 renderas="sect3" id="configfiles"> <title>What's the difference between the
918 <quote>Cautious</quote>, <quote>Medium</quote> and <quote>Advanced</quote> defaults?</title>
920 Configuring <application>Privoxy</application> is not entirely trivial. To
921 help you get started, we provide you with three different default action
922 <quote>profiles</quote> in the web based actions file editor at <ulink
923 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>.
924 See the <ulink url="../user-manual/actions-file.html"><citetitle>User
925 Manual</citetitle></ulink> for a list of actions, and how the default
930 Where the defaults are likely to break some sites, exceptions for
931 known popular <quote>problem</quote> sites are included, but in
932 general, the more aggressive your default settings are, the more exceptions
933 you will have to make later. New users are best to start off in
934 <quote>Cautious</quote> setting. This is safest and will have the fewest
935 problems. See the <ulink
936 url="../user-manual/index.html"><citetitle>User Manual</citetitle></ulink>
937 for a more detailed discussion.
941 It should be noted that the <quote>Advanced</quote> profile (formerly known
942 as the <quote>Adventuresome</quote> profile) is more
943 aggressive, and will make use of some of
944 <application>Privoxy's</application> advanced features. Use at your own risk!
949 <sect2 renderas="sect3" id="browseconfig"> <title>Why can I change the configuration
950 with a browser? Does that not raise security issues?</title>
952 It may seem strange that regular users can edit the config files with their
953 browsers, although the whole <filename>/etc/privoxy</filename> hierarchy
954 belongs to the user <quote>privoxy</quote>, with only 644 permissions.
957 When you use the browser-based editor, <application>Privoxy</application>
958 itself is writing to the config files. Because
959 <application>Privoxy</application> is running as the user <quote>privoxy</quote>,
960 it can update its own config files.
963 If you run <application>Privoxy</application> for multiple untrusted users (e.g. in
964 a LAN) or aren't entirely in control of your own browser, you will probably want
965 to make sure that the web-based editor and remote toggle features are
966 <quote>off</quote> by setting <quote><literal><ulink
967 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>
968 0</literal></quote> and <quote><literal><ulink
969 url="../user-manual/config.html#ENABLE-REMOTE-TOGGLE">enable-remote-toggle</ulink>
970 0</literal></quote> in the <ulink url="../user-manual/config.html">main configuration file</ulink>.
973 As of &my-app; 3.0.7 these options are disabled by default.
978 <sect2 renderas="sect3">
979 <title id="filterfile">What is the <filename>default.filter</filename> file? What is a <quote>filter</quote>?</title>
981 The <ulink url="../user-manual/filter-file.html"><filename>default.filter</filename></ulink>
982 file is where <emphasis>filters</emphasis> as supplied by the developers are defined.
983 Filters are a special subset of actions that can be used to modify or
984 remove web page content or headers on the fly. Content filters can
985 be applied to <emphasis>anything</emphasis> in the page source,
986 header filters can be applied to either server or client headers.
987 Regular expressions are used to accomplish this.
990 There are a number of pre-defined filters to deal with common annoyances. The
991 filters are only defined here, to invoke them, you need to use the
993 url="../user-manual/actions-file.html#FILTER"><literal>filter</literal>
994 action</ulink> in one of the actions files. Content filtering is automatically
995 disabled for inappropriate MIME types, but if you know better than Privoxy
996 what should or should not be filtered you can filter any content you like.
1000 <emphasis>not</emphasis> be confused with <ulink
1001 url="../user-manual/actions-file.html#BLOCK"><literal>blocks</literal></ulink>, which
1002 is a completely different action, and is more typically used to block ads and
1007 If you are familiar with regular expressions, and HTML, you can look at
1008 the provided <filename>default.filter</filename> with a text editor and define
1009 your own filters. This is potentially a very powerful feature, but
1010 requires some expertise in both regular expressions and HTML/HTTP.
1011 <![%p-newstuff;[ You should
1012 place any modifications to the default filters, or any new ones you create
1013 in a separate file, such as <filename>user.filter</filename>, so they won't
1014 be overwritten during upgrades.
1015 The ability to define multiple filter files
1016 in <filename>config</filename> is a new feature as of v. 3.0.5.]]>
1020 There is no GUI editor option for this part of the configuration,
1021 but you can disable/enable the various pre-defined filters of the included
1022 <filename>default.filter</filename> file with the <ulink
1023 url="http://config.privoxy.org/show-status">web-based actions file editor</ulink>.
1024 Note that the custom actions editor must be explicitly enabled in
1025 the main config file (see <ulink
1026 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>).
1030 If you intend to develop your own filters, you might want to have a look at
1032 url="http://www.fabiankeil.de/sourcecode/pft/">Privoxy-Filter-Test</ulink>.
1037 <sect2 renderas="sect3" id="lanconfig">
1038 <title>How can I set up Privoxy to act as a proxy for my
1041 By default, <application>Privoxy</application> only responds to requests
1042 from <literal>127.0.0.1</literal> (localhost). To have it act as a server for
1043 a network, this needs to be changed in the <ulink
1044 url="../user-manual/config.html">main configuration file</ulink>. Look for
1046 url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink></literal>
1047 option, which may be commented out with a <quote>#</quote> symbol. Make sure
1048 it is uncommented, and assign it the address of the LAN gateway interface,
1049 and port number to use. Assuming your LAN address is 192.168.1.1 and you
1050 wish to run <application>Privoxy</application> on port 8118, this line
1056 listen-address 192.168.1.1:8118</screen>
1060 Save the file, and restart <application>Privoxy</application>. Configure
1061 all browsers on the network then to use this address and port number.
1065 Alternately, you can have <application>Privoxy</application> listen on
1066 all available interfaces:
1071 listen-address :8118</screen>
1075 And then use <application>Privoxy's</application>
1077 url="../user-manual/config.html#PERMIT-ACCESS">permit-access</ulink>
1078 feature to limit connections. A firewall in this situation is recommended
1083 The above steps should be the same for any TCP network, regardless of
1088 If you run <application>Privoxy</application> on a LAN with untrusted users,
1089 we recommend that you double-check the <ulink
1090 url="../user-manual/config.html#ACCESS-CONTROL">access control and security</ulink>
1097 <sect2 renderas="sect3">
1098 <title id="noseeum">Instead of ads, now I get a checkerboard pattern. I don't want to see anything.</title>
1100 The replacement for blocked images can be controlled with the <ulink
1101 url="../user-manual/actions-file.html#SET-IMAGE-BLOCKER"><literal>set-image-blocker</literal>
1102 action</ulink>. You have the choice of a checkerboard pattern, a transparent 1x1 GIF
1103 image (aka <quote>blank</quote>), or a redirect to a custom image of your choice.
1104 Note that this choice only has effect for images which are blocked as images, i.e.
1105 whose URLs match both a <literal><ulink
1106 url="../user-manual/actions-file.html#HANDLE-AS-IMAGE">handle-as-image</ulink></literal>
1107 <emphasis>and</emphasis> <literal><ulink
1108 url="../user-manual/actions-file.html#BLOCK">block</ulink></literal> action.
1111 If you want to see nothing, then change the <ulink
1112 url="../user-manual/actions-file.html#SET-IMAGE-BLOCKER"><literal>set-image-blocker</literal>
1113 action</ulink> to <quote>blank</quote>. This can be done by editing the
1114 <filename>user.action</filename> file, or through the <ulink
1115 url="http://config.privoxy.org/show-status">web-based actions file editor</ulink>.
1120 <sect2 renderas="sect3">
1121 <title id="whyseeum">Why would anybody want to see a checkerboard pattern?</title>
1123 Remember that <link linkend="whatsanad">telling which image is an ad and which
1124 isn't</link>, is an educated guess. While we hope that the standard configuration
1125 is rather smart, it will make occasional mistakes. The checkerboard image is visually
1126 decent, and it shows you where images have been blocked, which can be very
1127 helpful in case some navigation aid or otherwise innocent image was
1128 erroneously blocked. It is recommended for new users so they can
1129 <quote>see</quote> what is happening. Some people might also enjoy seeing how
1130 many banners they <emphasis>don't</emphasis> have to see.
1135 <sect2 renderas="sect3">
1136 <title id="blockedbytext">I see some images being replaced with text
1137 instead of the checkerboard image. Why and how do I get rid of this?</title>
1139 This happens when the banners are not embedded in the HTML code of the
1140 page itself, but in separate HTML (sub)documents that are loaded into (i)frames
1141 or (i)layers, and these external HTML documents are blocked. Being non-images
1142 they get replaced by a substitute HTML page rather than a substitute image,
1143 which wouldn't work out technically, since the browser expects and accepts
1144 only HTML when it has requested an HTML document.
1147 The substitute page adapts to the available space and shows itself as a
1148 miniature two-liner if loaded into small frames, or full-blown with a
1149 large red "BLOCKED" banner if space allows.
1152 If you prefer the banners to be blocked by images, you must see to it that
1153 the HTML documents in which they are embedded are not blocked. Clicking
1154 the <quote>See why</quote> link offered in the substitute page will show
1155 you which rule blocked the page. After changing the rule and un-blocking
1156 the HTML documents, the browser will try to load the actual banner images
1157 and the usual image blocking will (hopefully!) kick in.
1162 <sect2 renderas="sect3" id="srvany">
1163 <title>Can Privoxy run as a service
1164 on Win2K/NT/XP?</title>
1167 Yes. Version 3.0.5 introduces full <application>Windows</application> service
1168 functionality. See <ulink url="../user-manual/installation.html#installation-pack-win">
1169 the <citetitle>User Manual</citetitle></ulink> for details on how to install and configure
1170 <application>Privoxy</application> as a service.
1173 Earlier ]]>3.x versions could run as a system service using <command>srvany.exe</command>.
1174 See the discussion at <ulink
1175 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>,
1176 for details, and a sample configuration.
1181 <sect2 renderas="sect3" id="otherproxy">
1182 <title>How can I make Privoxy work with other proxies?</title>
1184 This can be done and is often useful to combine the benefits of
1185 <application>Privoxy</application> with those of a another proxy,
1186 for example to cache content.
1188 url="../user-manual/config.html#FORWARDING">forwarding chapter</ulink>
1189 in the <ulink url="../user-manual/index.html">User Manual</ulink> which
1190 describes how to do this. If you intend to use Privoxy with Tor,
1191 please also have a look at
1192 <link linkend="TOR">How do I use Privoxy together with Tor</link>.
1196 <sect2 renderas="sect3" id="port-80">
1197 <title>Can I just set Privoxy to use port 80
1198 and thus avoid individual browser configuration?</title>
1201 No, its more complicated than that. This only works with special kinds
1202 of proxies known as <quote>intercepting</quote> proxies
1203 (<link linkend="INTERCEPTING">see below</link>).
1208 <sect2 renderas="sect3" id="transparent">
1209 <title>Can Privoxy run as a <quote>transparent
1210 </quote> proxy?</title>
1212 The whole idea of Privoxy is to modify client requests
1213 and server responses in all sorts of ways and therefore
1214 it's not a transparent proxy as described in
1215 <ulink url="http://tools.ietf.org/html/rfc2616">RFC 2616</ulink>.
1218 However, some people say <quote>transparent proxy</quote> when they
1219 mean <quote>intercepting proxy</quote>. If you are one of them,
1220 please read the <link linkend="INTERCEPTING">next entry</link>.
1225 <sect2 renderas="sect3" id="intercepting">
1226 <title>Can Privoxy run as a <quote>intercepting</quote> proxy?</title>
1228 <application>Privoxy</application> can't intercept traffic itself,
1229 but it can handle requests that where intercepted and redirected
1230 with a packet filter (like <application>PF</application> or
1231 <application>iptables</application>), as long as the <literal>Host</literal>
1235 As the <literal>Host</literal> header is required by HTTP/1.1 and as most
1236 web sites rely on it anyway, this limitation shouldn't be a problem.
1239 Please refer to your packet filter's documentation to learn how to
1240 intercept and redirect traffic into <application>Privoxy</application>.
1241 Afterward you just have to configure <application>Privoxy</application> to
1242 <ulink url="../user-manual/config.html#ACCEPT-INTERCEPTED-REQUESTS">accept
1243 intercepted requests</ulink>.
1248 <sect2 renderas="sect3" id="outlook">
1249 <title>How can I configure Privoxy for use with Outlook?</title>
1251 Versions of <application>Outlook</application> prior to Office 2007, use
1252 <application>Internet Explorer</application> components to both render HTML,
1253 and fetch any HTTP requests that may be embedded in an HTML email. So however
1254 you have <application>Privoxy</application> configured to work with IE, this
1255 configuration should automatically be shared, at least with older version of
1259 Starting with Office 2007, Microsoft is instead using the MS-Word rendering
1260 engine with Outlook. It is unknown whether this can be configured to use a
1262 <!-- FIXME HB 2009-02-15 -->
1266 <sect2 renderas="sect3" id="outlook-more">
1267 <title>How can I have separate rules just for HTML mail?</title>
1269 The short answer is, you can't. <application>Privoxy</application> has no way
1270 of knowing which particular application makes a request, so there is no way to
1271 distinguish between web pages and HTML mail.
1272 <application>Privoxy</application> just blindly proxies all requests. In the
1273 case of <application>Outlook Express</application> (see above), OE uses
1274 IE anyway, and there is no way for <application>Privoxy</application> to ever
1275 be able to distinguish between them (nor could any other proxy type application for
1279 For a good discussion of some of the issues involved (including privacy and
1280 security issues), see
1281 <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>.
1285 <sect2 renderas="sect3" id="sneaky-cookies">
1286 <title>I sometimes notice cookies sneaking through. How?</title>
1289 url="http://en.wikipedia.org/wiki/Browser_cookie">Cookies</ulink> can be
1290 set in several ways. The classic method is via the
1291 <literal>Set-Cookie</literal> HTTP header. This is straightforward, and an
1292 easy one to manipulate, such as the &my-app; concept of
1293 <ulink url="../user-manual/actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</ulink>.
1294 There is also the possibility of using
1295 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink> to
1296 set cookies (&my-app; calls these <literal>content-cookies</literal>). This
1297 is trickier because the syntax can vary widely, and thus requires a certain
1298 amount of guesswork. It is not realistic to catch all of these short of
1299 disabling Javascript, which would break many sites. And lastly, if the
1300 cookies are embedded in a HTTPS/SSL secure session via Javascript, they are beyond
1301 <application>Privoxy's</application> reach.
1304 All in all, &my-app; can help manage cookies in general, can help minimize
1305 the loss of privacy posed by cookies, but can't realistically stop all
1310 <sect2 renderas="sect3" id="evil-cookies">
1311 <title>Are all cookies bad? Why?</title>
1313 No, in fact there are many beneficial uses of
1315 url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>. Cookies are just a
1316 method that browsers can use to store data between pages, or between browser
1317 sessions. Sometimes there is a good reason for this, and the user's life is a
1318 bit easier as a result. But there is a long history of some websites taking
1319 advantage of this layer of trust, and using the data they glean from you and
1320 your browsing habits for their own purposes, and maybe to your potential
1321 detriment. Such sites are using you and storing their data on your system.
1322 That is why the privacy conscious watch from whom those cookies come, and why
1323 they really <emphasis>need</emphasis> to be there.
1327 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">Wikipedia cookie
1328 definition</ulink> for more.
1332 <sect2 renderas="sect3" id="allow-cookies">
1333 <title>How can I allow permanent cookies for my trusted sites?</title>
1336 There are several actions that relate to cookies. The default behavior is to
1337 allow only <quote>session cookies</quote>, which means the cookies only last
1338 for the current browser session. This eliminates most kinds of abuse related
1339 to cookies. But there may be cases where you want cookies to last.
1342 To disable all cookie actions, so that cookies are allowed unrestricted,
1343 both in and out, for <literal>example.com</literal>:
1347 { -crunch-incoming-cookies -crunch-outgoing-cookies -session-cookies-only -filter{content-cookies} }
1348 .example.com</screen>
1351 Place the above in <filename>user.action</filename>. Note that some of these may
1352 be off by default anyway, so this might be redundant, but there is no harm
1353 being explicit in what you want to happen. <filename>user.action</filename>
1354 includes an alias for this situation, called
1355 <literal>allow-all-cookies</literal>.
1359 <sect2 renderas="sect3" id="multiples">
1360 <title>Can I have separate configurations for different users?</title>
1362 Each instance of <application>Privoxy</application> has its own
1363 configuration, including such attributes as the TCP port that it listens on.
1364 What you can do is run multiple instances of <application>Privoxy</application>, each with
1366 <ulink url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink>
1367 configuration setting, and configuration path, and then
1368 each of these can have their own configurations. Think of it as per-port
1372 Simple enough for a few users, but for large installations, consider having
1373 groups of users that might share like configurations.
1377 <sect2 renderas="sect3" id="whitelists">
1378 <title>Can I set-up Privoxy as a whitelist of
1379 <quote>good</quote> sites?</title>
1381 Sure. There are a couple of things you can do for simple white-listing.
1382 Here's one real easy one:
1385 ############################################################
1387 ############################################################
1388 { <ulink url="../user-manual/actions-file.html#BLOCK">+block</ulink> }
1389 / # Block *all* URLs
1391 ############################################################
1393 ############################################################
1394 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> }
1397 games.example.com</screen>
1399 This allows access to only those three sites by first blocking all URLs, and
1400 then subsequently allowing three specific exceptions.
1403 Another approach is <application>Privoxy's</application>
1404 <literal>trustfile</literal> concept, which incorporates the notion of
1405 <quote>trusted referrers</quote>. See the <ulink
1406 url="../user-manual/config.html#TRUSTFILE">Trust documentation</ulink>
1410 These are fairly simple approaches and are not completely foolproof. There
1411 are various other configuration options that should be disabled (described
1412 elsewhere here and in <ulink url="../user-manual/">the User Manual</ulink>)
1413 so that users can't modify their own configuration and easily circumvent the
1418 <sect2 renderas="sect3" id="no-adblock">
1419 <title>How can I turn off ad-blocking?</title>
1421 Ad blocking is achieved through a complex application of various &my-app;
1422 <ulink url="../user-manual/actions-file.html">actions</ulink>. These
1423 actions are deployed against simple images, banners, flash animations,
1424 text pages, JavaScript, pop-ups and pop-unders, etc., so its not as simple as
1425 just turning one or two actions off. The various actions that make up
1426 &my-app; ad blocking are hard-coded into the default configuration files. It
1427 has been assumed that everyone using &my-app; is interested in this
1431 If you want to do without this, there are several approaches you can take:
1432 You can manually undo the many block rules in
1433 <filename>default.action</filename>. Or even easier, just create your own
1434 <filename>default.action</filename> file from scratch without the many ad
1435 blocking rules, and corresponding exceptions. Or lastly, if you are not
1436 concerned about the additional blocks that are done for privacy reasons, you
1437 can very easily over-ride <emphasis>all</emphasis> blocking with the
1438 following very simple rule in your <filename>user.action</filename>:
1442 # Unblock everybody, everywhere
1443 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> }
1444 / # UN-Block *all* URLs</screen>
1447 Or even a more comprehensive reversing of various ad related actions:
1451 # Unblock everybody, everywhere, and turn off appropriate filtering, etc
1452 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> \
1453 <ulink url="../user-manual/actions-file.html#FILTER-BANNERS-BY-SIZE">-filter{banners-by-size}</ulink> \
1454 <ulink url="../user-manual/actions-file.html#FILTER-BANNERS-BY-LINK">-filter{banners-by-link}</ulink> \
1455 <literal>allow-popups</literal> \
1457 / # UN-Block *all* URLs and allow ads</screen>
1460 This last <quote>action</quote> in this compound statement,
1461 <literal>allow-popups</literal>, is an <ulink
1462 url="../user-manual/actions-file.html#ALIASES">alias</ulink> that disables
1463 various pop-up blocking features.
1467 <sect2 renderas="sect3" id="templates">
1468 <title>How can I have custom template pages, like the
1469 <emphasis>BLOCKED</emphasis> page?</title>
1471 &my-app; <quote>templates</quote> are specialized text files utilized by
1472 &my-app; for various purposes and can easily be modified using any text
1473 editor. All the template pages are installed in a sub-directory appropriately
1474 named: <filename>templates</filename>. Knowing something about HTML syntax
1475 will of course be helpful.
1478 Be forewarned that the default templates are subject to being overwritten
1479 during upgrades. You can, however, create completely new templates,
1480 place them in another directory and specify the alternate path in the main
1481 <filename>config</filename>. For details, have a look at the <ulink
1482 url="../user-manual/config.html#templdir">templdir</ulink> option.
1486 <sect2 renderas="sect3" id="blockall">
1487 <title>How can I remove the <quote>Go There Anyway</quote> link from
1488 the <emphasis>BLOCKED</emphasis> page?</title>
1490 There is more than one way to do it (although Perl is not involved).
1493 Editing the BLOCKED template page (see above) may dissuade some users, but
1494 this method is easily circumvented. Where you need this level of control, you
1495 might want to build &my-app; from source, and disable various features that are
1496 available as compile-time options. You should
1497 <command>configure</command> the sources as follows:
1501 ./configure --disable-toggle --disable-editor --disable-force</screen>
1504 This will create an executable with hard-coded security features so that
1505 &my-app; does not allow easy bypassing of blocked sites, or changing the
1506 current configuration via any connected user's web browser.
1509 Finally, all of these features can also be toggled on/off via options in
1510 <application>Privoxy's</application> main <ulink
1511 url="../user-manual/config.html#ACCESS-CONTROL">config</ulink> file which
1512 means you don't have to recompile anything.
1518 <!-- ~ End section ~ -->
1521 <!-- ~~~~~ New section ~~~~~ -->
1523 <sect1 id="misc"><title>Miscellaneous</title>
1525 <sect2 renderas="sect3">
1526 <title id="slowsme">How much does Privoxy slow my browsing down? This
1527 has to add extra time to browsing.</title>
1529 How much of an impact depends on many things, including the CPU of the host
1530 system, how aggressive the configuration is, which specific actions are being triggered,
1531 the size of the page, the bandwidth of the connection, etc.
1534 Overall, it should not slow you down any in real terms, and may actually help
1535 speed things up since ads, banners and other junk are not typically being
1536 retrieved and displayed. The actual processing time required by
1537 <application>Privoxy</application> itself for each page, is relatively small
1538 in the overall scheme of things, and happens very quickly. This is typically
1539 more than offset by time saved not downloading and rendering ad images and
1540 other junk content (if ad blocking is being used).
1544 <quote>Filtering</quote> content via the <literal><ulink
1545 url="../user-manual/actions-file.html#FILTER">filter</ulink></literal> or
1547 url="../user-manual/actions-file.html#DEANIMATE-GIFS">deanimate-gifs</ulink></literal>
1548 actions may cause a perceived slowdown, since the entire document
1549 needs to be buffered before displaying. And on very large documents,
1550 filtering may have some measurable impact. How much depends on the page size,
1551 the actual definition of the filter(s), etc. See below. Most other actions
1552 have little to no impact on speed.
1555 Also, when filtering is enabled but zlib support isn't available, compression
1556 is often disabled (see <ulink
1557 url="../user-manual/actions-file.html#PREVENT-COMPRESSION">prevent-compression</ulink>).
1558 This can have an impact on speed as well, although it's probably smaller than
1559 you might think. Again, the page size, etc. will determine how much of an impact.
1565 <sect2 renderas="sect3" id="loadingtimes"><title>I notice considerable
1566 delays in page requests. What's wrong?</title>
1568 If you use any <literal><ulink
1569 url="../user-manual/actions-file.html#FILTER">filter</ulink></literal> action,
1570 such as filtering banners by size, web-bugs etc, or the <literal><ulink
1571 url="../user-manual/actions-file.html#DEANIMATE-GIFS">deanimate-gifs</ulink></literal>
1572 action, the entire document must be loaded into memory in order for the filtering
1573 mechanism to work, and nothing is sent to the browser during this time.
1576 The loading time typically does not really change much in real numbers, but
1577 the feeling is different, because most browsers are able to start rendering
1578 incomplete content, giving the user a feeling of "it works". This effect is
1579 more noticeable on slower dialup connections. Extremely large documents
1580 may have some impact on the time to load the page where there is filtering
1581 being done. But overall, the difference should be very minimal. If there is a
1582 big impact, then probably some other situation is contributing (like
1583 anti-virus software).
1586 Filtering is automatically disabled for inappropriate MIME types. But note
1587 that if the web server mis-reports the MIME type, then content that should
1588 not be filtered, could be. <application>Privoxy</application> only knows how
1589 to differentiate filterable content because of the MIME type as reported by
1590 the server, or because of some configuration setting that enables/disables
1595 <sect2 renderas="sect3" id="configurl"><title>What are "http://config.privoxy.org/" and
1596 "http://p.p/"?</title>
1598 <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink> is the
1599 address of <application>Privoxy</application>'s built-in user interface, and
1600 <ulink url="http://p.p/">http://p.p/</ulink> is a shortcut for it.
1603 Since <application>Privoxy</application> sits between your web browser and the Internet,
1604 it can simply intercept requests for these addresses and answer them with its built-in
1605 <quote>web server</quote>.
1608 This also makes for a good test for your browser configuration: If entering the
1609 URL <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
1610 takes you to a page saying <quote>This is Privoxy ...</quote>, everything is OK.
1611 If you get a page saying <quote>Privoxy is not working</quote> instead, then
1612 your browser didn't use <application>Privoxy</application> for the request,
1613 hence it could not be intercepted, and you have accessed the <emphasis>real</emphasis>
1614 web site at config.privoxy.org.
1620 out of date 09/02/06 HB
1621 <sect2 renderas="sect3" id="blocklist"><title>Do you still maintain the blocklists?</title>
1623 No. The patterns for blocking now reside (among other things) in the <ulink
1624 url="../user-manual/actions-file.html">actions files</ulink>, which are
1625 actively maintained instead. See next question ...
1629 <sect2 renderas="sect3" id="newads"><title>How can I submit new ads, or report
1632 Please see the <link linkend="contact">Contact section</link> for
1633 various ways to interact with the developers.
1638 <sect2 renderas="sect3" id="newads2"><title>If I do submit missed ads, will
1639 they be included in future updates?</title>
1641 Whether such submissions are eventually included in the
1642 <filename>default.action</filename> configuration file depends on how
1643 significant the issue is. We of course want to address any potential
1644 problem with major, high-profile sites such as <citetitle>Google</citetitle>,
1645 <citetitle>Yahoo</citetitle>, etc. Any site with global or regional reach,
1646 has a good chance of being a candidate. But at the other end of the spectrum
1647 are any number of smaller, low-profile sites such as for local clubs or
1648 schools. Since their reach and impact are much less, they are best handled by
1649 inclusion in the user's <filename>user.action</filename>, and thus would be
1650 unlikely to be included.
1656 <sect2 renderas="sect3" id="noonecares"><title>Why doesn't anyone answer my support
1659 Rest assured that it has been read and considered. Why it is not answered,
1660 could be for various reasons, including no one has a good answer for it, no
1661 one has had time to yet investigate it thoroughly, it has been reported
1662 numerous times already, or because not enough information was provided to help
1663 us help you. Your efforts are not wasted, and we do appreciate them.
1669 <sect2 renderas="sect3" id="ip"><title>How can I hide my IP address?</title>
1671 If you run both the browser and &my-app; locally, you cannot hide your IP
1672 address with <application>Privoxy</application> or ultimately any other
1673 software alone. The server needs to know your IP address so that it knows
1674 where to send the responses back.
1677 There are many publicly usable "anonymous" proxies out there, which
1678 provide a further level of indirection between you and the web server.
1681 However, these proxies are called "anonymous" because you don't need
1682 to authenticate, not because they would offer any real anonymity.
1683 Most of them will log your IP address and make it available to the
1684 authorities in case you violate the law of the country they run in. In fact
1685 you can't even rule out that some of them only exist to *collect* information
1686 on (those suspicious) people with a more than average preference for privacy.
1689 If you want to hide your IP address from most adversaries,
1690 you should consider chaining <application>Privoxy</application>
1691 with <ulink url="https://www.torproject.org/">Tor</ulink>.
1692 The configuration details can be found in
1693 <ulink url="#TOR">How do I use <application>Privoxy</application> together
1694 with <application>Tor</application> section</ulink>
1699 <sect2 renderas="sect3">
1700 <title id="anonforsure">Can Privoxy guarantee I am anonymous?</title>
1702 No. Your chances of remaining anonymous are improved, but unless you
1703 <ulink url="#TOR">chain <application>Privoxy</application> with <application>Tor</application></ulink>
1704 or a similar proxy and know what you're doing when it comes to configuring
1705 the rest of your system, you should assume that everything you do
1706 on the Web can be traced back to you.
1709 <application>Privoxy</application> can remove various information about you,
1710 and allows <emphasis>you</emphasis> more freedom to decide which sites
1711 you can trust, and what details you want to reveal. But it neither
1712 hides your IP address, nor can it guarantee that the rest of the system
1713 behaves correctly. There are several possibilities how a web sites can find
1714 out who you are, even if you are using a strict <application>Privoxy</application>
1715 configuration and chained it with <application>Tor</application>.
1718 Most of <application>Privoxy's</application> privacy-enhancing features can be easily subverted
1719 by an insecure browser configuration, therefore you should use a browser that can
1720 be configured to only execute code from trusted sites, and be careful which sites you trust.
1721 For example there is no point in having <application>Privoxy</application>
1722 modify the User-Agent header, if websites can get all the information they want
1723 through JavaScript, ActiveX, Flash, Java etc.
1726 A few browsers disclose the user's email address in certain situations, such
1727 as when transferring a file by FTP. <application>Privoxy</application>
1728 does not filter FTP. If you need this feature, or are concerned about the
1729 mail handler of your browser disclosing your email address, you might
1730 consider products such as <application>NSClean</application>.
1733 Browsers available only as binaries could use non-standard headers to give
1734 out any information they can have access to: see the manufacturer's license
1735 agreement. It's impossible to anticipate and prevent every breach of privacy
1736 that might occur. The professionally paranoid prefer browsers available as
1737 source code, because anticipating their behavior is easier. Trust the source,
1743 <sect2 renderas="sect3">
1744 <title id="proxytest">A test site says I am not using a Proxy.</title>
1746 Good! Actually, they are probably testing for some other kinds of proxies.
1747 Hiding yourself completely would require additional steps.
1751 <sect2 renderas="sect3" id="tor"><title>How do I use Privoxy
1752 together with Tor?</title>
1754 Before you configure <application>Privoxy</application> to use
1755 <ulink url="https://www.torproject.org/">Tor</ulink>,
1756 please follow the <citetitle>User Manual</citetitle> chapters
1757 <ulink url="../user-manual/installation.html">2. Installation</ulink> and
1758 <ulink url="../user-manual/startup.html">5. Startup</ulink> to make sure
1759 <application>Privoxy</application> itself is setup correctly.
1762 If it is, refer to <ulink url="https://www.torproject.org/documentation.html">Tor's
1763 extensive documentation</ulink> to learn how to install <application>Tor</application>,
1764 and make sure <application>Tor</application>'s logfile says that
1765 <quote>Tor has successfully opened a circuit</quote> and it
1766 <quote>looks like client functionality is working</quote>.
1769 If either <application>Tor</application> or <application>Privoxy</application>
1770 isn't working, their combination most likely will neither. Testing them on their
1771 own will also help you to direct problem reports to the right audience.
1772 If <application>Privoxy</application> isn't working, don't bother the
1773 <application>Tor</application> developers. If <application>Tor</application>
1774 isn't working, don't send bug reports to the <application>Privoxy</application> Team.
1777 If you verified that <application>Privoxy</application> and <application>Tor</application>
1778 are working, it is time to connect them. As far as <application>Privoxy</application>
1779 is concerned, <application>Tor</application> is just another proxy that can be reached
1780 by socks4, socks4a and socks5. Most likely you are interested in <application>Tor</application>
1781 to increase your anonymity level, therefore you should use socks5, to make sure DNS
1782 requests are done through <application>Tor</application> and thus invisible to your
1783 local network. Using socks4a would work too, but with socks5 you get more precise error
1788 <application>Privoxy's</application>
1789 <ulink url="../user-manual/config.html">main configuration file</ulink>
1790 is already prepared for <application>Tor</application>, if you are using a
1791 default <application>Tor</application> configuration and run it on the same
1792 system as &my-app;, you just have to edit the
1793 <ulink url="../user-manual/config.html#FORWARDING">forwarding section</ulink>
1794 and uncomment the line:
1798 # forward-socks5t / 127.0.0.1:9050 .
1802 Note that if you got Tor through one of the bundles, you may
1803 have to change the port from 9050 to 9150 (or even another one).
1804 For details, please check the documentation on the
1805 <ulink url="https://torproject.org/">Tor website</ulink>.
1809 This is enough to reach the Internet, but additionally you might want to
1810 uncomment the following forward rules, to make sure your local network is still
1811 reachable through Privoxy:
1815 # forward 192.168.*.*/ .
1816 # forward 10.*.*.*/ .
1817 # forward 127.*.*.*/ .
1821 Unencrypted connections to systems in these address ranges will
1822 be as (un)secure as the local network is, but the alternative is
1823 that your browser can't reach the network at all. Then again,
1824 that may actually be desired and if you don't know for sure
1825 that your browser has to be able to reach the local network,
1826 there's no reason to allow it.
1829 If you want your browser to be able to reach servers in your local
1830 network by using their names, you will need additional exceptions
1831 that look like this:
1835 # forward localhost/ .
1839 Save the modified configuration file and open
1840 <ulink url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
1841 in your browser, confirm that <application>Privoxy</application> has reloaded its configuration
1842 and that there are no other forward lines, unless you know that you need them. If everything looks good,
1844 <ulink url="https://wiki.torproject.org/noreply/TheOnionRouter/TorFAQ#IsMyConnectionPrivate">Tor
1845 Faq 4.2</ulink> to learn how to verify that you are really using <application>Tor</application>.
1848 Afterward, please take the time to at least skim through the rest
1849 of <application>Tor's</application> documentation. Make sure you understand
1850 what <application>Tor</application> does, why it is no replacement for
1851 application level security, and why you probably don't want to
1852 use it for unencrypted logins.
1856 <sect2 renderas="sect3">
1857 <title id="sitebreak">Might some things break because header information or
1858 content is being altered?</title>
1861 Definitely. It is common for sites to use browser type, browser version,
1862 HTTP header content, and various other techniques in order to dynamically
1863 decide what to display and how to display it. What you see, and what I see,
1864 might be very different. There are many, many ways that this can be handled,
1865 so having hard and fast rules, is tricky.
1869 The <quote>User-Agent</quote> is sometimes used in this way to identify
1870 the browser, and adjust content accordingly.
1874 Also, different browsers use different encodings of non-English
1875 characters, certain web servers convert pages on-the-fly according to the
1876 User Agent header. Giving a <quote>User Agent</quote> with the wrong
1877 operating system or browser manufacturer causes some sites in these languages
1878 to be garbled; Surfers to Eastern European sites should change it to
1879 something closer. And then some page access counters work by looking at the
1880 <quote>Referer</quote> header; they may fail or break if unavailable. The
1881 weather maps of Intellicast have been blocked by their server when no
1882 <quote>Referer</quote> or cookie is provided, is another example. (But you
1883 can forge both headers without giving information away). There are
1884 many other ways things can go wrong when trying to fool a web server. The
1885 results of which could inadvertently cause pages to load incorrectly,
1886 partially, or even not at all. And there may be no obvious clues as to just
1887 what went wrong, or why. Nowhere will there be a message that says
1888 <quote><emphasis>Turn off <literal>fast-redirects</literal> or else!</emphasis>
1893 Similar thoughts apply to modifying JavaScript, and, to a lesser degree,
1898 If you have problems with a site, you will have to adjust your configuration
1899 accordingly. Cookies are probably the most likely adjustment that may
1900 be required, but by no means the only one.
1906 <sect2 renderas="sect3">
1907 <title id="caching">Can Privoxy act as a <quote>caching</quote> proxy to
1908 speed up web browsing?</title>
1910 No, it does not have this ability at all. You want something like
1911 <ulink url="http://www.squid-cache.org/">Squid</ulink> or
1912 <ulink url="http://www.pps.jussieu.fr/~jch/software/polipo/">Polipo</ulink> for this.
1913 And, yes, before you ask, <application>Privoxy</application> can co-exist
1914 with other kinds of proxies like <application>Squid</application>.
1915 See the <ulink url="../user-manual/config.html#FORWARDING">forwarding
1916 chapter</ulink> in the <ulink url="../user-manual/index.html">user
1917 manual</ulink> for details.
1921 <sect2 renderas="sect3">
1922 <title id="firewall">What about as a firewall? Can Privoxy protect me?</title>
1924 Not in the way you mean, or in the way some firewall vendors claim they can.
1925 <application>Privoxy</application> can help protect your privacy, but can't
1926 protect your system from intrusion attempts. It is, of course, perfectly possible
1927 to use <emphasis>both</emphasis>.
1931 <sect2 renderas="sect3">
1932 <title id="wasted">I have large empty spaces / a checkerboard pattern now where
1933 ads used to be. Why?</title>
1935 It is technically possible to eliminate banners and ads in a way that frees
1936 their allocated page space. This could easily be done by blocking with
1937 <application>Privoxy's</application> filters,
1938 and eliminating the <emphasis>entire</emphasis> image references from the
1942 But, this would consume considerably more CPU resources (IOW, slow things
1943 down), would likely destroy the layout of some web pages which rely on the
1944 banners utilizing a certain amount of page space, and might fail in other
1945 cases, where the screen space is reserved (e.g. by HTML tables for instance).
1946 Also, making ads and banners disappear without any trace complicates
1947 troubleshooting, and would sooner or later be problematic.
1950 The better alternative is to instead let them stay, and block the resulting
1951 requests for the banners themselves as is now the case. This leaves either
1952 empty space, or the familiar checkerboard pattern.
1955 So the developers won't support this in the default configuration, but you
1956 can of course define appropriate filters yourself to achieve this.
1960 <sect2 renderas="sect3">
1961 <title id="ssl">How can Privoxy filter Secure (HTTPS) URLs?</title>
1963 Since secure HTTP connections are encrypted SSL sessions between your browser
1964 and the secure site, and are meant to be reliably <emphasis>secure</emphasis>,
1965 there is little that <application>Privoxy</application> can do but hand the raw
1966 gibberish data though from one end to the other unprocessed.
1969 The only exception to this is blocking by host patterns, as the client needs
1970 to tell <application>Privoxy</application> the name of the remote server,
1971 so that <application>Privoxy</application> can establish the connection.
1972 If that name matches a host-only pattern, the connection will be blocked.
1975 As far as ad blocking is concerned, this is less of a restriction than it may
1976 seem, since ad sources are often identifiable by the host name, and often
1977 the banners to be placed in an encrypted page come unencrypted nonetheless
1978 for efficiency reasons, which exposes them to the full power of
1979 <application>Privoxy</application>'s ad blocking.
1982 <quote>Content cookies</quote> (those that are embedded in the actual HTML or
1983 JS page content, see <literal><ulink
1984 url="../user-manual/actions-file.html#FILTER-CONTENT-COOKIES">filter{content-cookies}</ulink></literal>),
1985 in an SSL transaction will be impossible to block under these conditions.
1986 Fortunately, this does not seem to be a very common scenario since most
1987 cookies come by traditional means.
1992 <sect2 renderas="sect3">
1993 <title id="secure">Privoxy runs as a <quote>server</quote>. How
1994 secure is it? Do I need to take any special precautions?</title>
1996 On Unix-like systems, <application>Privoxy</application> can run as a non-privileged
1997 user, which is how we recommend it be run. Also, by default
1998 <application>Privoxy</application> listens to requests from <quote>localhost</quote>
2002 The server aspect of <application>Privoxy</application> is not itself directly
2003 exposed to the Internet in this configuration. If you want to have
2004 <application>Privoxy</application> serve as a LAN proxy, this will have to
2005 be opened up to allow for LAN requests. In this case, we'd recommend
2006 you specify only the LAN gateway address, e.g. 192.168.1.1, in the main
2007 <application>Privoxy</application> configuration file and check all <ulink
2008 url="../user-manual/config.html#ACCESS-CONTROL">access control and security
2009 options</ulink>. All LAN hosts can then use this as their proxy address
2010 in the browser proxy configuration, but <application>Privoxy</application>
2011 will not listen on any external interfaces. ACLs can be defined in addition,
2012 and using a firewall is always good too. Better safe than sorry.
2017 <sect2 renderas="sect3" id="turnoff">
2018 <title>Can I temporarily disable Privoxy?</title>
2020 &my-app; doesn't have a transparent proxy mode,
2021 but you can toggle off blocking and content filtering.
2024 The easiest way to do that is to point your browser
2025 to the remote toggle URL: <ulink
2026 url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>.
2029 See the <ulink url="../user-manual/appendix.html#BOOKMARKLETS">Bookmarklets section</ulink>
2030 of the <citetitle>User Manual</citetitle> for an easy way to access this
2031 feature. Note that this is a feature that may need to be enabled in the main
2032 <filename>config</filename> file.
2037 <sect2 renderas="sect3" id="reallyoff">
2038 <title>When <quote>disabled</quote> is Privoxy totally
2039 out of the picture?</title>
2041 No, this just means all optional filtering and actions are disabled.
2042 <application>Privoxy</application> is still acting as a proxy, but just
2043 doing less of the things that <application>Privoxy</application> would
2044 normally be expected to do. It is still a <quote>middle-man</quote> in
2045 the interaction between your browser and web sites. See below to bypass
2050 <sect2 renderas="sect3" id="turnoff2">
2051 <title>How can I tell Privoxy to totally ignore certain sites?</title>
2053 Bypassing a proxy, or proxying based on arbitrary criteria, is purely a browser
2054 configuration issue, not a &my-app; issue. Modern browsers typically do have
2055 settings for not proxying certain sites. Check your browser's help files.
2060 <sect2 renderas="sect3" id="crunch">
2061 <title>My logs show Privoxy <quote>crunches</quote>
2062 ads, but also its own internal CGI pages. What is a <quote>crunch</quote>?</title>
2064 A <quote>crunch</quote> simply means <application>Privoxy</application> intercepted
2065 <emphasis>something</emphasis>, nothing more. Often this is indeed ads or
2066 banners, but <application>Privoxy</application> uses the same mechanism for
2067 trapping requests for its own internal pages. For instance, a request for
2068 <application>Privoxy's</application> configuration page at: <ulink
2069 url="http://config.privoxy.org">http://config.privoxy.org</ulink>, is
2070 intercepted (i.e. it does not go out to the 'net), and the familiar CGI
2071 configuration is returned to the browser, and the log consequently will show
2072 a <quote>crunch</quote>.
2075 Since version 3.0.7, Privoxy will also log the crunch reason.
2076 If you are using an older version you might want to upgrade.
2080 <sect2 renderas="sect3" id="downloads">
2081 <title>Can Privoxy effect files that I download
2082 from a webserver? FTP server?</title>
2084 From the webserver's perspective, there is no difference between
2085 viewing a document (i.e. a page), and downloading a file. The same is true of
2086 <application>Privoxy</application>. If there is a match for a <literal><ulink
2087 url="../user-manual/actions-file.html#BLOCK">block</ulink></literal> pattern,
2088 it will still be blocked, and of course this is obvious.
2091 Filtering is potentially more of a concern since the results are not always
2092 so obvious, and the effects of filtering are there whether the file is simply
2093 viewed, or downloaded. And potentially whether the content is some obnoxious
2094 advertisement, or Mr. Jimmy's latest/greatest source code jewel. Of course,
2095 one of these presumably is <quote>bad</quote> content that we don't want, and
2096 the other is <quote>good</quote> content that we do want.
2097 <application>Privoxy</application> is blind to the differences, and can only
2098 distinguish <quote>good from bad</quote> by the configuration parameters
2099 <emphasis>we</emphasis> give it.
2102 <application>Privoxy</application> knows the differences in files according
2103 to the <quote>Content Type</quote> as reported by the webserver. If this is
2104 reported accurately (e.g. <quote>application/zip</quote> for a zip archive),
2105 then <application>Privoxy</application> knows to ignore these where
2106 appropriate. <application>Privoxy</application> potentially can filter HTML
2107 as well as plain text documents, subject to configuration parameters of
2108 course. Also, documents that are of an unknown type (generally assumed to be
2109 <quote>text/plain</quote>) can be filtered, as will those that might be
2110 incorrectly reported by the webserver. If such a file is a downloaded file
2111 that is intended to be saved to disk, then any content that might have been
2112 altered by filtering, will be saved too, for these (probably rare) cases.
2115 Note that versions later than 3.0.2 do NOT filter document types reported as
2116 <quote>text/plain</quote>. Prior to this, <application>Privoxy</application>
2117 did filter this document type.
2120 In short, filtering is <quote>ON</quote> if a) the content type as reported
2121 by the webserver is appropriate <emphasis>and</emphasis> b) the configuration
2122 allows it (or at least does not disallow it). That's it. There is no magic
2123 cookie anywhere to say this is <quote>good</quote> and this is
2124 <quote>bad</quote>. It's the configuration that lets it all happen or not.
2127 If you download text files, you probably do not want these to be filtered,
2128 particularly if the content is source code, or other critical content. Source
2129 code sometimes might be mistaken for Javascript (i.e. the kind that might
2130 open a pop-up window). It is recommended to turn off filtering for download
2131 sites (particularly if the content may be plain text files and you are using
2132 version 3.0.2 or earlier) in your <filename>user.action</filename> file. And
2133 also, for any site or page where making <emphasis>any</emphasis> changes at
2134 all to the content is to be avoided.
2137 <application>Privoxy</application> does not do FTP at all, only HTTP
2138 and HTTPS (SSL) protocols.
2142 <sect2 renderas="sect3" id="downloads2">
2143 <title>I just downloaded a Perl script, and Privoxy
2144 altered it! Yikes, what is wrong!</title>
2150 <sect2 renderas="sect3" id="hostsfile">
2151 <title>Should I continue to use a <quote>HOSTS</quote> file for ad-blocking?</title>
2153 One time-tested technique to defeat common ads is to trick the local DNS
2154 system by giving a phony IP address for the ad generator in the local
2155 <filename>HOSTS</filename> file, typically using <literal>127.0.0.1</literal>, aka
2156 <literal>localhost</literal>. This effectively blocks the ad.
2159 There is no reason to use this technique in conjunction with
2160 <application>Privoxy</application>. <application>Privoxy</application>
2161 does essentially the same thing, much more elegantly and with much more
2162 flexibility. A large <filename>HOSTS</filename> file, in fact, not only
2163 duplicates effort, but may get in the way and seriously slow down your system.
2164 It is recommended to remove such entries from your <filename>HOSTS</filename> file. If you think
2165 your hosts list is neglected by <application>Privoxy's </application>
2166 configuration, consider adding your list to your <filename>user.action</filename> file:
2173 ads.galore.example.com
2174 etc.example.com</screen>
2178 <sect2 renderas="sect3" id="seealso">
2179 <title>Where can I find more information about Privoxy
2180 and related issues?</title>
2181 <!-- Include seealso.sgml boilerplate: -->
2183 <!-- end boilerplate -->
2188 <ulink url="../user-manual/seealso.html">user-manual</ulink> for
2194 <sect2 renderas="sect3" id="microsuck">
2195 <title>I've noticed that Privoxy changes <quote>Microsoft</quote> to
2196 <quote>MicroSuck</quote>! Why are you manipulating my browsing?</title>
2199 We're not. The text substitutions that you are seeing are disabled
2200 in the default configuration as shipped. You have either manually
2201 activated the <quote><literal>fun</literal></quote> filter which
2202 is clearly labeled <quote>Text replacements for subversive browsing
2203 fun!</quote> or you are using an older Privoxy version and have implicitly
2204 activated it by choosing the <quote>Advanced</quote> profile in the
2205 web-based editor. Please upgrade.
2209 <sect2 renderas="sect3" id="valid">
2210 <title>Does Privoxy produce <quote>valid</quote> HTML (or XHTML)?</title>
2213 Privoxy generates HTML in both its own <quote>templates</quote>, and possibly
2214 whenever there are text substitutions via a &my-app; filter. While this
2215 should always conform to the HTML 4.01 specifications, it has not been
2216 validated against this or any other standard.
2220 <sect2 renderas="sect3" id="surprise-privoxy">
2221 <title>How did you manage to get Privoxy on my computer without my consent?</title>
2224 We didn't. We make Privoxy available for download, but we don't go
2225 around installing it on other people's systems behind their back.
2226 If you discover Privoxy running on your system and are sure you didn't
2227 install it yourself, somebody else did. You may not even be running
2228 the real Privoxy, but maybe something else that only pretends to be
2229 Privoxy, or maybe something that is based on the real Privoxy,
2230 but has been modified.
2233 Lately there have been reports of problems with some kind of
2234 Privoxy versions that come preinstalled on some Netbooks.
2235 Some of the problems described are inconsistent with the behaviour
2236 of official Privoxy versions, which suggests that the preinstalled
2237 software may contain vendor modifications that we don't know about
2238 and thus can't debug.
2241 Privoxy's <link linkend="copyright">license</link> allows vendor
2242 modifications, but the vendor has to comply with the license,
2243 which involves informing the user about the changes and to make
2244 the changes available under the same license as Privoxy itself.
2247 If you are having trouble with a modified Privoxy version,
2248 please try to talk to whoever made the modifications before
2249 reporting the problem to us. Please also try to convince
2250 whoever made the modifications to talk to us. If you think
2251 somebody gave you a modified Privoxy version without complying
2252 to the license, please let us know.
2260 <!-- ~~~~~ New section ~~~~~ -->
2262 <sect1 id="trouble">
2263 <title>Troubleshooting</title>
2265 <sect2 renderas="sect3">
2266 <title id="refused">I cannot connect to any websites. Or, I am getting
2267 <quote>connection refused</quote> message with every web page. Why?</title>
2269 There are several possibilities:
2274 <application>Privoxy</application> is not running. Solution: verify
2275 that &my-app; is installed correctly, has not crashed, and is indeed running.
2276 Turn on <application>Privoxy's</application> logging, and look at the logs to see what they say.
2278 <listitem><para>Or your browser is configured for a different port than what
2279 <application>Privoxy</application> is using. Solution: verify that &my-app;
2280 and your browser are set to the same port (<literal>listen-address</literal>).
2282 <listitem><para>Or if using a forwarding rule, you have a configuration problem or a
2283 problem with a host in the forwarding chain. Solution: temporarily alter your
2284 configuration and take the forwarders out of the equation.
2287 Or you have a firewall that is interfering and blocking you. Solution:
2288 try disabling or removing the firewall as a simple test.
2295 <!-- ~~~~~ New section ~~~~~ -->
2296 <sect2 renderas="sect3" id="error503">
2297 <title>Why am I getting a 503 Error (WSAECONNREFUSED) on every page?</title>
2299 More than likely this is a problem with your TCP/IP networking. ZoneAlarm has
2300 been reported to cause this symptom -- even if not running! The solution is
2301 to either fight the ZA configuration, or uninstall ZoneAlarm, and then find
2302 something better behaved in its place. Other personal firewall type products
2303 may cause similar type problems if not configured correctly.
2307 <sect2 renderas="sect3">
2308 <title id="flushit">I just added a new rule, but the steenkin ad is
2309 still getting through. How?</title>
2311 If the ad had been displayed before you added its URL, it will probably be
2312 held in the browser's cache for some time, so it will be displayed without
2313 the need for any request to the server, and <application>Privoxy</application>
2314 will not be involved. Flush the browser's caches, and then try again.
2318 If this doesn't help, you probably have an error in the rule you
2319 applied. Try pasting the full URL of the offending ad into <ulink
2320 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
2321 and see if it really matches your new rule. Blocking ads is like blocking
2322 spam: a lot of tinkering is required to stay ahead of the game. And
2323 remember you need to block the URL of the ad in question, which may be
2324 entirely different from the site URL itself. Most ads are hosted on different
2325 servers than the main site itself. If you right-click on the ad, you should
2326 be able to get all the relevant information you need. Alternately, you can
2327 find the correct URL by looking at <application>Privoxy's</application> logs
2328 (you may need to enable logging in the main config file if its disabled).
2331 Below is a slightly modified real-life log snippet that originates with one
2332 requested URL: <literal>www.example.com</literal> (name of site was changed
2333 for this example, the number of requests is real). You can see in this the
2334 complexity of what goes into making up this one <quote>page</quote>. There
2335 are eight different domains involved here, with thirty two separate URLs
2336 requested in all, making up all manner of images, Shockwave Flash,
2337 JavaScript, CSS stylesheets, scripts, and other related content. Some of this
2338 content is obviously <quote>good</quote> or <quote>bad</quote>, but not all.
2339 Many of the more questionable looking requests, are going to outside domains
2340 that seem to be identifying themselves with suspicious looking names, making
2341 our job a little easier. &my-app; has <quote>crunched</quote> (meaning caught
2342 and BLOCKED) quite a few items in this example, but perhaps missed a few as well.
2347 Request: www.example.com/
2348 Request: www.example.com/favicon.ico
2349 Request: img.example.com/main.css
2350 Request: img.example.com/sr.js
2351 Request: example.betamarker.com/example.html
2352 Request: www.lik-sang.com/Banners/bestsellers/skyscraper.php?likref=BSellers
2353 Request: img.example.com/pb.png
2354 Request: www.google-analytics.com/urchin.js crunch! (Blocked)
2355 Request: www.advertising-department.com/ats/switch.ps.php?26856 crunch! (Blocked)
2356 Request: img.example.com/p.gif
2357 Request: www.popuptraffic.com/assign.php?l=example&mode=behind crunch! (Blocked)
2358 Request: www.popuptraffic.com/scripts/popup.php?hid=5c3cf&tmpl=PBa.tmpl crunch! (Blocked)
2359 Request: www.popuptraffic.com/assign.php?l=example crunch! (Blocked)
2360 Request: www.lik-sang.com/Banners/best_sellers/best_sellers.css
2361 Request: www.adtrak.net/adx.js crunch! (Blocked)
2362 Request: img.example.com/hbg.gif
2363 Request: img.example.com/example.jpg
2364 Request: img.example.com/mt.png
2365 Request: img.example.com/mm.png
2366 Request: img.example.com/mb.png
2367 Request: www.popuptraffic.com/scripts/popup.php?hid=a71b91fa5&tmpl=Ua.tmp crunch! (Blocked)
2368 Request: www.example.com/tracker.js
2369 Request: www.lik-sang.com/Banners/best_sellers/lsi_head.gif
2370 Request: www.adtrak.net/adjs.php?n=020548130&what=zone:61 crunch! (Blocked)
2371 Request: www.adtrak.net/adjs.php?n=463594413&what=zone:58&source=Ua crunch! (Blocked)
2372 Request: www.lik-sang.com/Banners/best_sellers/bottomani.swf
2373 Request: mmm.elitemediagroup.net/install.php?allowpop=no&popupmincook=0&allowsp2=1 crunch! (Blocked)
2374 Request: www.example.com/tracker.js?screen=1400x1050&win=962x693
2375 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=61 crunch! (Blocked)
2376 Request: 66.70.21.80/scripts/click.php?hid=5c3cf599a9efd0320d26&si
2377 Request: 66.70.21.80/img/pixel.gif
2378 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=58&source=Ua&block=86400 crunch! (Blocked)
2379 Request: 66.70.21.80/scripts/click.php?hid=a71b9f6504b0c5681fa5&si=Ua
2384 Despite 12 out of 32 requests being blocked, the page looked, and seemed to
2385 behave perfectly <quote>normal</quote> (minus some ads, of course).
2390 <sect2 id="badsite" renderas="sect3">
2391 <title >One of my favorite sites does not work with Privoxy.
2392 What can I do?</title>
2395 First verify that it is indeed a <application>Privoxy</application> problem,
2396 by toggling off <application>Privoxy</application> through <ulink
2397 url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>
2398 (the toggle feature may need to be enabled in the main
2399 <filename>config</filename>),
2400 and then shift-reloading the problem page (i.e. holding down the shift key
2401 while clicking reload. Alternatively, flush your browser's disk and memory
2406 If the problem went away, we know we have a configuration related problem.
2408 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
2409 and paste the full URL of the page in question into the prompt. See which
2410 actions are being applied to the URL, and which matches in which actions
2411 files are responsible for that. It might be helpful also to look at your logs
2412 for this site too, to see what else might be happening (note: logging may need
2413 to be enabled in the main config file). Many sites are
2414 complex and require a number of related pages to help present their content.
2415 Look at what else might be used by the page in question, and what of that
2416 might be <emphasis>required</emphasis>.
2417 Now, armed with this information, go to
2419 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
2420 and select the appropriate actions files for editing. </para>
2422 You can now either look for a section which disables the actions that
2423 you suspect to cause the problem and add a pattern for your site there,
2424 or make up a completely new section for your site. In any case, the recommended
2425 way is to disable only the prime suspect, reload the problem page, and only
2426 if the problem persists, disable more and more actions until you have
2427 identified the culprit. You may or may not want to turn the other actions
2428 on again. Remember to flush your browser's caches in between any such changes!
2431 Alternately, if you are comfortable with a text editor, you can accomplish
2432 the same thing by editing the appropriate actions file. Probably the easiest
2433 way to deal with such problems when editing by hand is to add your
2434 site to a <literal>{ fragile }</literal> section in <filename>user.action</filename>,
2435 which is an alias that turns off most <quote>dangerous</quote>
2436 actions, but is also likely to turn off more actions then needed, and thus lower
2437 your privacy and protection more than necessary,
2440 Troubleshooting actions is discussed in more detail in the <ulink
2441 url="../user-manual/appendix.html#ACTIONSANAT">User Manual appendix,
2442 Troubleshooting: the Anatomy of an Action</ulink>.
2443 There is also an <ulink
2444 url="../user-manual/actions-file.html#ACT-EXAMPLES">actions tutorial</ulink>
2445 with general configuration information and examples.
2448 As a last resort, you can always see if your browser has a setting that will
2449 bypass the proxy setting for selective sites. Modern browsers can do this.
2455 <!-- ~~~~~ New section ~~~~~ -->
2456 <sect2 id="dun" renderas="sect3">
2457 <title>After installing Privoxy, I have to log in
2458 every time I start IE. What gives?</title>
2461 This is a quirk that effects the installation of
2462 <application>Privoxy</application>, in conjunction with Internet Explorer and
2463 Internet Connection Sharing on Windows 2000 and Windows XP. The symptoms may
2464 appear to be corrupted or invalid DUN settings, or passwords.
2468 When setting up an NT based Windows system with
2469 <application>Privoxy</application> you may find that things do not seem to be
2470 doing what you expect. When you set your system up you will probably have set
2471 up Internet Connection Sharing (ICS) with Dial up Networking (DUN) when
2472 logged in with administrator privileges. You will probably have made this DUN
2473 connection available to other accounts that you may have set-up on your
2474 system. E.g. Mum or Dad sets up the system and makes accounts suitably
2475 configured for the kids.
2479 When setting up <application>Privoxy</application> in this environment you
2480 will have to alter the proxy set-up of Internet Explorer (IE) for the
2481 specific DUN connection on which you wish to use
2482 <application>Privoxy</application>. When you do this the ICS DUN set-up
2483 becomes user specific. In this instance you will see no difference if you
2484 change the DUN connection under the account used to set-up the connection.
2485 However when you do this from another user you will notice that the DUN
2486 connection changes to make available to "Me only". You will also find that
2487 you have to store the password under each different user!
2491 The reason for this is that each user's set-up for IE is user specific. Each
2492 set-up DUN connection and each LAN connection in IE store the settings for
2493 each user individually. As such this enforces individual configurations
2494 rather than common ones. Hence the first time you use a DUN connection after
2495 re-booting your system it may not perform as you expect, and prompt you for
2496 the password. Just set and save the password again and all should be OK.
2500 [Thanks to Ray Griffith for this submission.]
2505 <!-- ~~~~~ New section ~~~~~ -->
2506 <sect2 id="ftp" renderas="sect3">
2507 <title>I cannot connect to any FTP sites. Privoxy
2508 is blocking me.</title>
2510 <application>Privoxy</application> cannot act as a proxy for FTP traffic,
2511 so do not configure your browser to use <application>Privoxy</application>
2512 as an FTP proxy. The same is true for <emphasis>any protocol other than HTTP
2513 or HTTPS (SSL)</emphasis>.
2516 Most browsers understand FTP as well as HTTP. If you connect to a site, with
2517 a URL like <literal>ftp://ftp.example.com</literal>, your browser is making
2518 an FTP connection, and not a HTTP connection. So while your browser may
2519 speak FTP, <application>Privoxy</application> does not, and cannot proxy
2523 To complicate matters, some systems may have a generic <quote>proxy</quote>
2524 setting, which will enable various protocols, including
2525 <emphasis>both</emphasis> HTTP and FTP proxying! So it is possible to
2526 accidentally enable FTP proxying in these cases. And of course, if this
2527 happens, <application>Privoxy</application> will indeed cause problems since
2528 it does not know FTP. <![%p-newstuff;[Newer version will give a sane error
2529 message if a FTP connection is attempted.]]> Just disable the FTP setting
2530 and all will be well again.
2533 Will <application>Privoxy</application> ever proxy FTP traffic? Unlikely.
2534 There just is not much reason, and the work to make this happen is more than
2539 <!-- ~~~~~ New section ~~~~~ -->
2540 <sect2 id="macosxie" renderas="sect3">
2541 <title>In Mac OS X, I can't configure Microsoft Internet Explorer to use
2542 Privoxy as the HTTP proxy.</title>
2544 Microsoft Internet Explorer (in versions like 5.1) respects system-wide
2545 network settings. In order to change the HTTP proxy, open System
2546 Preferences, and click on the Network icon. In the settings pane that
2547 comes up, click on the Proxies tab. Ensure the "Web Proxy (HTTP)" checkbox
2548 is checked and enter <literal>127.0.0.1</literal> in the entry field.
2549 Enter <literal>8118</literal> in the Port field. The next time you start
2550 IE, it should reflect these values.
2554 <!-- ~~~~~ New section ~~~~~ -->
2555 <sect2 renderas="sect3" id="macosxuninstall">
2556 <title>In Mac OS X, I dragged the Privoxy folder to the trash in order to
2557 uninstall it. Now the finder tells me I don't have sufficient privileges to
2558 empty the trash.</title>
2560 Note: This ONLY applies to privoxy 3.0.6 and earlier.
2563 Just dragging the <application>Privoxy</application> folder to the trash is
2564 not enough to delete it. <application>Privoxy</application> supplies an
2565 <application>uninstall.command</application> file that takes care of
2566 these details. Open the trash, drag the <application>uninstall.command</application>
2567 file out of the trash and double-click on it. You will be prompted for
2568 confirmation and the administration password.
2571 The trash may still appear full after this command; emptying the trash
2572 from the desktop should make it appear empty again.
2576 <!-- ~~~~~ New section ~~~~~ -->
2577 <sect2 renderas="sect3" id="macosximages">
2578 <title>In Mac OS X Panther (10.3), images often fail to load and/or I
2579 experience random delays in page loading. I'm using
2580 <literal>localhost</literal> as my browser's proxy setting.</title>
2582 We believe this is due to an IPv6-related bug in Mac OS X, but don't fully
2583 understand the issue yet. In any case, changing the proxy setting to
2584 <literal>127.0.0.1</literal> instead of <literal>localhost</literal>
2585 works around the problem.
2589 <!-- ~~~~~ New section ~~~~~ -->
2590 <sect2 renderas="sect3" id="macosxaccountdeletion">
2591 <title>I just upgraded to Mac OS X 10.9 (Mavericks) and now &my-app; has stopped
2594 The upgrade process to Mac OS X Mavericks (10.9) from an earlier version of OS
2595 X deletes all user accounts that are either not part of OS X itself or are
2596 not interactive user accounts (ones you log in with). Since, for the sake of
2597 security, &my-app; runs as a non-privileged user that is created by its
2598 installer (_privoxy), it can no longer start up once that account gets deleted.
2599 The solution is to perform a complete uninstall using the supplied
2600 <application>uninstall.command</application> script (either back up your
2601 configuration files or select to not have the uninstaller remove them when it
2602 prompts you) and then reinstall &my-app; using the installer package and merge
2603 in your configuration.
2607 <!-- ~~~~~ New section ~~~~~ -->
2608 <!-- XXX: Is this still relevant now that we have gzip support? -->
2609 <sect2 renderas="sect3" id="blankpage">
2610 <title>I get a completely blank page at one site. <quote>View Source</quote>
2611 shows only: <markup><![CDATA[<html><body></body></html>]]></markup>. Without
2612 Privoxy the page loads fine.</title>
2614 Chances are that the site suffers from a bug in
2615 <ulink url="http://www.php.net/"><application>PHP</application></ulink>,
2616 which results in empty pages being sent if the client explicitly requests
2617 an uncompressed page, like <application>Privoxy</application> does.
2618 This bug has been fixed in PHP 4.2.3.
2621 To find out if this is in fact the source of the problem, try adding
2622 the site to a <literal>-prevent-compression</literal> section in
2623 <filename>user.action</filename>:
2626 # Make exceptions for ill-behaved sites:
2628 {-prevent-compression}
2629 .example.com</screen>
2631 If that works, you may also want to report the problem to the
2632 site's webmasters, telling them to use zlib.output_compression
2633 instead of ob_gzhandler in their PHP applications (workaround)
2634 or upgrade to PHP 4.2.3 or later (fix).
2638 <sect2 renderas="sect3" id="nohostname">
2639 <title>My logs show many <quote>Unable to get my own hostname</quote> lines.
2642 <application>Privoxy</application> tries to get the hostname of the system
2643 its running on from the IP address of the system interface it is bound to
2644 (from the <filename>config</filename> file
2645 <emphasis>listen-address</emphasis> setting). If the system cannot supply
2646 this information, <application>Privoxy</application> logs this condition.
2649 Typically, this would be considered a minor system configuration error. It is
2650 not a fatal error to <application>Privoxy</application> however, but may
2651 result in a much slower response from <application>Privoxy</application> on
2652 some platforms due to DNS timeouts.
2655 This can be caused by a problem with the local <filename>hosts</filename>
2656 file. If this file has been changed from the original, try reverting it to
2657 see if that helps. Make sure whatever name(s) are used for the local system,
2658 that they resolve both ways.
2661 You should also be able to work around the problem with the
2662 <ulink url="../user-manual/config.html#HOSTNAME">hostname option</ulink>.
2666 <sect2 renderas="sect3" id="inuse">
2667 <title>When I try to launch Privoxy, I get an
2668 error message <quote>port 8118 is already in use</quote> (or similar wording).
2671 Port 8118 is <application>Privoxy's</application> default TCP
2672 <quote>listening</quote> port. Typically this message would mean that there
2673 is already one instance of <application>Privoxy</application> running, and
2674 your system is actually trying to start a second
2675 <application>Privoxy</application> on the same port, which will not work.
2676 (You can have multiple instances but they must be assigned different ports.)
2677 How and why this might happen varies from platform to platform, but you need
2678 to check your installation and start-up procedures.
2682 <sect2 renderas="sect3" id="demoronizer">
2684 Pages with UTF-8 fonts are garbled.
2687 This may be the result of an overly aggressive filter. The filters that
2688 are enabled in the default configuration aren't expected to cause problems
2689 like this. If you enabled the <quote>demoronizer</quote> filter, please
2690 try temporarily disabling it.
2693 If that doesn't help, temporarily disable all filters to see if another
2694 filter could be the culprit. If the problem disappears, enable the filters
2695 one by one, until the problem reappears and the offending filter is found.
2698 Once the problem-causing filter is known, it can be fixed or disabled.
2701 Upgrading <application>Privoxy</application>, or going to the most recent
2702 <filename>default.action</filename> file available from <ulink
2703 url="http://sourceforge.net/project/showfiles.php?group_id=11118">SourceForge</ulink>
2704 might be worth a try, too.
2708 <sect2 renderas="sect3" id="demoronizer2">
2710 Why are binary files (such as images) corrupted when Privoxy
2714 This may also be caused by an (<link linkend="DEMORONIZER">overly aggressive
2715 filter</link> in conjunction with a web server that is misreporting the content
2716 type. By default binary files are exempted from
2717 <application>Privoxy's</application> filtering
2718 (unless the web server by mistake says the file is something else).
2722 <sect2 renderas="sect3" id="demoronizer3">
2724 What is the <quote>demoronizer</quote> and why is it there?
2727 The original demoronizer was a Perl script that cleaned up HTML pages which
2728 were created with certain Microsoft products. MS has used proprietary extensions
2729 to standardized font encodings (ISO 8859-1), which has caused problems for pages
2730 that are viewed with non-Microsoft products (and are expecting to see a
2731 standard set of fonts). The demoronizer corrected these errors so the pages
2732 displayed correctly. <application>Privoxy</application> borrowed from this
2733 script, introducing a filter based on the original demoronizer, which in turn could
2734 correct these errors on the fly.
2737 But this is only needed in some situations, and will cause serious problems in some
2741 If you are using Microsoft products, you do not need it. If you need to view
2742 pages with UTF-8 characters (such as Cyrillic or Chinese), then it will
2743 cause corruption of the fonts, and thus <emphasis>should not be on</emphasis>.
2746 On the other hand, if you use non-Microsoft products, and you occasionally
2747 notice weird characters on pages, you might want to try it.
2751 <sect2 renderas="sect3" id="windowopen">
2753 Why do I keep seeing <quote>PrivoxyWindowOpen()</quote> in raw source code?
2756 <application>Privoxy</application> is attempting to disable malicious
2757 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink>
2758 in this case, with the <literal>unsolicited-popups</literal>
2759 filter. <application>Privoxy</application> cannot tell very well
2760 <quote>good</quote> code snippets from <quote>bad</quote> code snippets.
2763 If you see this in HTML source, and the page displays without problems, then
2764 this is good, and likely some pop-up window was disabled. If you see this
2765 where it is causing a problem, such as a downloaded program source code file,
2766 then you should set an exception for this site or page such that the
2767 integrity of the page stays in tact by disabling all filtering.
2771 <sect2 renderas="sect3" id="dnserrors">
2773 I am getting too many DNS errors like <quote>404 No Such Domain</quote>. Why
2774 can't Privoxy do this better?
2777 There are potentially several factors here. First of all, the DNS resolution
2778 is done by the underlying operating system -- not
2779 <application>Privoxy</application> itself. <application>Privoxy</application>
2780 merely initiates the process and hands it off, and then later reports
2781 whatever the outcome was and tries to give a coherent message if there seems
2782 to be a problem. In some cases, this might otherwise be mitigated by the
2783 browser itself which might try some work-arounds and alternate approaches (e.g
2784 adding <quote>www.</quote> to the URL).
2787 In other cases, if <application>Privoxy</application> is being chained
2788 with another proxy, this could complicate the issue, and cause undue
2789 delays and timeouts. In the case of a <quote>socks4a</quote> proxy, the socks
2790 server handles all the DNS. <application>Privoxy</application> would just be
2791 the <quote>messenger</quote> which is reporting whatever problem occurred
2792 downstream, and not the root cause of the error.
2796 In any case, versions newer than 3.0.3 include various improvements to help
2797 <application>Privoxy</application> better handle these cases.
2801 <sect2 renderas="sect3" id="allcpu">
2803 At one site Privoxy just hangs, and starts taking
2804 all CPU. Why is this?
2807 This is probably a manifestation of the <quote>100% cpu</quote> problem that
2808 occurs on pages containing many (thousands upon thousands) of blank lines. The blank lines
2809 are in the raw HTML source of the page, and the browser just ignores them. But the
2810 pattern matching in <application>Privoxy's</application> page filtering
2811 mechanism is trying to match against absurdly long strings and this becomes
2812 very CPU-intensive, taking a long, long time to complete.
2815 Until a better solution comes along, disable filtering on these pages,
2816 particularly the <literal>js-annoyances</literal> and
2817 <literal>unsolicited-popups</literal> filters. If you run into this problem
2818 with a recent &my-app; version, please send a problem report.
2822 <sect2 renderas="sect3" id="slowcrawl">
2823 <title>I just installed Privoxy, and all my
2824 browsing has slowed to a crawl. What gives? </title>
2826 This should not happen, and for the overwhelming number of users world-wide,
2827 it does not happen. I would suspect some inadvertent interaction of software
2828 components such as anti-virus software, spyware protectors, personal
2829 firewalls or similar components. Try disabling (or uninstalling) these one
2830 at a time and see if that helps. Either way, if you are using a
2831 recent &my-app; version, please report the problem.
2835 <sect2 renderas="sect3" id="preventcomp">
2836 <title>Why do my filters work on some sites but not on others? </title>
2838 It's probably due to compression. It is a common practice for web servers to
2839 send their content <quote>compressed</quote> in order to speed things up, and
2840 then let the browser <quote>uncompress</quote> them. When compiled with zlib support
2841 &my-app; can decompress content before filtering, otherwise you may want to enable
2843 url="../user-manual/actions-file.html#PREVENT-COMPRESSION">prevent-compression</ulink>.
2846 As of &my-app; 3.0.9, zlib support is enabled in the default builds.
2851 <sect2 renderas="sect3" id="ssl-warnings">
2852 <title>On some HTTPS sites my browser warns me about unauthenticated content,
2853 the URL bar doesn't get highlighted and the lock symbol appears to be broken.
2854 What's going on?</title>
2856 Probably the browser is requesting ads through HTTPS and &my-app;
2857 is blocking the requests. Privoxy's error messages are delivered
2858 unencrypted and while it's obvious for the browser that the HTTPS
2859 request is already blocked by the proxy, some warn about unauthenticated
2863 To work around the problem you can redirect those requests to an invalid
2864 local address instead of blocking them. While the redirects aren't
2865 encrypted either, many browsers don't care. They simply follow the
2866 redirect, fail to reach a server and display an error message instead
2870 To do that, enable logging to figure out which requests get blocked by
2871 &my-app; and add the hosts (no path patterns) to a section like this:
2876 {+redirect{http://127.0.0.1:0/} -block -limit-connect}
2882 Additionally you have to configure your browser to contact
2883 <quote>127.0.0.1:0</quote> directly (instead of through &my-app;).
2886 To add a proxy exception in <application>Mozilla Firefox</application>
2887 open the <quote>Preferences</quote>, click the <quote>Settings</quote>
2888 button located on the <quote>Network</quote> tab in the <quote>Advanced</quote>
2889 section, and add <quote>127.0.0.1:0</quote> in the <quote>No Proxy for:</quote>
2895 <sect2 renderas="sect3" id="se-linux">
2896 <title>I get selinux error messages. How can I fix this?</title>
2898 Please report the problem to the creator of your selinux policies.
2901 The problem is that some selinux policy writers aren't familiar
2902 with the application they are trying to <quote>secure</quote> and
2903 thus create policies that make no sense.
2906 In <application>Privoxy's</application> case the problem usually
2907 is that the policy only allows outgoing connections for certain
2908 destination ports (e.g. 80 and 443). While this may cover the
2909 standard ports, websites occasionally use other ports as well.
2910 This isn't a security problem and therefore <application>Privoxy's</application>
2911 default configuration doesn't block these requests.
2914 If you really want to block these ports (and don't be able
2915 to load websites that don't use standard ports), you should
2916 configure Privoxy to block these ports as well, so it doesn't
2917 trigger the selinux warnings.
2922 <sect2 renderas="sect3" id="gentoo-ricers">
2923 <title>I compiled &my-app; with Gentoo's portage and it appears to be very slow. Why?</title>
2925 Probably you unintentionally compiled &my-app; without threading support
2926 in which case requests have to be serialized and only one can be served
2930 Check your <quote>USE</quote> flags and make sure they include
2931 <quote>threads</quote>. If they don't, add the flag and rebuild &my-app;.
2934 If you compiled &my-app; with threading support (on POSIX-based systems),
2935 the <quote>Conditional #defines</quote> section on <ulink
2936 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
2937 will list <quote>FEATURE_PTHREAD</quote> as <quote>enabled</quote>.
2944 <!-- ~~~~~ New section ~~~~~ -->
2945 <sect1 id="contact"><title>Contacting the developers, Bug Reporting and Feature Requests</title>
2946 <!-- Include contacting.sgml -->
2948 <!-- end contacting -->
2951 <!-- ~~~~~ New section ~~~~~ -->
2952 <sect1 id="copyright"><title>Privoxy Copyright, License and History</title>
2954 <!-- Include copyright.sgml -->
2960 Portions of this document are <quote>borrowed</quote> from the original
2961 <application>Junkbuster</application> (tm) FAQ, and modified as
2962 appropriate for <application>Privoxy</application>.
2965 <!-- ~~~~~ New section ~~~~~ -->
2966 <sect2><title>License</title>
2967 <!-- Include copyright.sgml: -->
2969 <!-- end copyright -->
2971 <!-- ~ End section ~ -->
2973 <!-- ~~~~~ New section ~~~~~ -->
2974 <sect2><title>History</title>
2975 <!-- Include history.sgml -->
2981 <!-- ~ End section ~ -->
2984 <!-- ~~~~~ New section ~~~~~ -->
2986 <sect1 id="seealso"><title>See also</title>
2988 <!-- Include seealso.sgml -->
2998 This program is free software; you can redistribute it
2999 and/or modify it under the terms of the GNU General
3000 Public License as published by the Free Software
3001 Foundation; either version 2 of the License, or (at
3002 your option) any later version.
3004 This program is distributed in the hope that it will
3005 be useful, but WITHOUT ANY WARRANTY; without even the
3006 implied warranty of MERCHANTABILITY or FITNESS FOR A
3007 PARTICULAR PURPOSE. See the GNU General Public
3008 License for more details.
3010 The GNU General Public License should be included with
3011 this file. If not, you can view it at
3012 http://www.gnu.org/copyleft/gpl.html
3013 or write to the Free Software Foundation, Inc.,
3014 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA