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 2.106 2014/12/19 12:31:28 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 2.106 2014/12/19 12:31:28 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 or a "Paypal" address:
527 Name on account: <ulink url="https://www.zwiebelfreunde.de/">Zwiebelfreunde e.V.</ulink>
528 IBAN: DE95430609671126825604
533 "Paypal" address: privoxy@zwiebelfreunde.de
536 Donations made through Zwiebelfreunde e.V. are tax-deductible in Germany
537 and other countries that recognize German charitable clubs. Feel free to
538 use the Subject field to provide a name to be credited and a list of TODO
539 list items you are interested in the most. For example: Max Mustermann: #16, #1, #14.
543 If you have any questions regarding donations please mail to either the
544 public user mailing list or, if it's a private matter, to
545 <ulink url="mailto:fk@fabiankeil.de">Fabian Keil</ulink> (Privoxy's SPI liason)
554 <!-- ~~~~~ New section ~~~~~ -->
556 <sect1 id="installation"><title>Installation</title>
558 <sect2 renderas="sect3" id="whichbrowsers">
559 <title>Which browsers are supported by Privoxy?</title>
561 Any browser that can be configured to use a proxy, which
562 should be virtually all browsers, including
563 <application>Firefox</application>, <application>Internet
564 Explorer</application>, <application>Opera</application>, and
565 <application>Safari</application> among others.
566 Direct browser support is not an absolute requirement since
567 <application>Privoxy</application> runs as a separate application and talks
568 to the browser in the standardized HTTP protocol, just like a web server
573 <sect2 renderas="sect3" id="whichos">
574 <title>Which operating systems are supported?</title>
576 Include supported.sgml here:
581 <sect2 renderas="sect3" id="email-client">
582 <title>Can I use Privoxy with my email client?</title>
584 As long as there is some way to set a HTTP proxy for the client, then yes,
585 any application can be used, whether it is strictly speaking a
586 <quote>browser</quote> or not. Though this may not be the best approach for
587 dealing with some of the common abuses of HTML in email. See <link
588 linkend="outlook">How can I configure <application>Privoxy</application>
589 with <application>Outlook</application>?</link> below for more on
593 Be aware that HTML email presents a number of unique security and privacy
594 related issues, that can require advanced skills to overcome. The developers
595 recommend using email clients that can be configured to convert HTML to plain
596 text for these reasons.
600 <!-- Nobody is going to still be doing this!
601 <sect2 renderas="sect3" id="newinstall"><title>Can I install
602 Privoxy over Junkbuster?</title>
604 We recommend you un-install <application>Junkbuster</application>
605 first to minimize conflicts and confusion. You may want to
606 save your old configuration files for future reference. The configuration
607 files and syntax have substantially changed, so you will need to manually
608 port your old patterns. See the <ulink url="../user-manual/upgradersnote.html">note
609 to upgraders</ulink> and <ulink url="../user-manual/installation.html">installation
610 chapter</ulink> in the <ulink url="../user-manual/index.html">User Manual</ulink>
614 Note: Some installers may automatically un-install
615 <application>Junkbuster</application>, if present!
621 <sect2 renderas="sect3" id="firststep">
622 <title>I just installed Privoxy. Is there anything
623 special I have to do now?</title>
626 All browsers should be told to use <application>Privoxy</application>
627 as a proxy by specifying the correct proxy address and port number
628 in the appropriate configuration area for the browser. It's possible
629 to combine &my-app; with a packet filter to intercept HTTP requests
630 even if the client isn't explicitly configured to use &my-app;,
631 but where possible, configuring the client is recommended. See
632 <ulink url="../user-manual/startup.html">the User Manual for more
633 details</ulink>. You should also flush your browser's memory and disk
634 cache to get rid of any cached junk items, and remove any stored
635 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>.
641 <sect2 renderas="sect3" id="localhost"><title>What is the proxy address of Privoxy?</title>
643 If you set up the <application>Privoxy</application> to run on
644 the computer you browse from (rather than your ISP's server or some
645 networked computer on a LAN), the proxy will be on <literal>127.0.0.1</literal>
646 (sometimes referred to as <quote>localhost</quote>,
647 which is the special name used by every computer on the Internet to refer
648 to itself) and the port will be 8118 (unless you used the <ulink
649 url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink>
650 config option to tell <application>Privoxy</application> to run on
654 When configuring your browser's proxy settings you typically enter
655 the word <quote>localhost</quote> or the IP address <quote>127.0.0.1</quote>
656 in the boxes next to <quote>HTTP</quote> and <quote>Secure</quote> (HTTPS) and
657 then the number <quote>8118</quote> for <quote>port</quote>.
658 This tells your browser to send all web requests to <application>Privoxy</application>
659 instead of directly to the Internet.
662 <application>Privoxy</application> can also be used to proxy for
663 a Local Area Network. In this case, your would enter either the IP
664 address of the LAN host where <application>Privoxy</application>
665 is running, or the equivalent hostname, e.g. <literal>192.168.1.1</literal>.
666 Port assignment would be same as above. Note that
667 <application>Privoxy</application> doesn't listen on any LAN interfaces by
671 <application>Privoxy</application> does not currently handle
672 any other protocols such as FTP, SMTP, IM, IRC, ICQ, etc.
676 <sect2 renderas="sect3" id="nothing">
677 <title>I just installed Privoxy, and nothing is happening.
678 All the ads are there. What's wrong?</title>
681 Did you configure your browser to use <application>Privoxy</application>
682 as a proxy? It does not sound like it. See above. You might also try flushing
683 the browser's caches to force a full re-reading of pages. You can verify
684 that <application>Privoxy</application> is running, and your browser
685 is correctly configured by entering the special URL:
686 <ulink url="http://p.p/">http://p.p/</ulink>.
687 <!-- Use http://p.p/ instead of http://config.privoxy.org/ here because
688 of potential redirect caching problem (see next Q). -->
689 This should take you to a page titled <quote>This is Privoxy..</quote> with
690 access to <application>Privoxy's</application> internal configuration.
691 If you see this, then you are good to go. If you receive a page saying
692 <quote>Privoxy is not running</quote>, then the browser is not set up to use
693 your <application>Privoxy</application> installation.
694 If you receive anything else (probably nothing at all), it could either
695 be that the browser is not set up correctly, or that
696 <application>Privoxy</application> is not running at all. Check the <ulink
697 url="../user-manual/config.html#LOGFILE">log file</ulink>. For instructions
698 on starting <application>Privoxy</application> and browser configuration,
699 see the <ulink url="http://www.privoxy.org/user-manual/startup.html">chapter
700 on starting <application>Privoxy</application></ulink> in the
701 <ulink url="http://www.privoxy.org/user-manual/">User Manual</ulink>.
706 <sect2 renderas="sect3" id="notused">
707 <title>I get a <quote>Privoxy is not being used</quote> dummy page although
708 Privoxy is running and being used.</title>
711 First, make sure that Privoxy is <emphasis>really</emphasis> running and
712 being used by visiting <ulink url="http://p.p/">http://p.p/</ulink>. You
713 should see the <application>Privoxy</application> main page. If not, see
714 the <ulink url="http://www.privoxy.org/user-manual/startup.html">chapter
715 on starting <application>Privoxy</application></ulink> in the
716 <ulink url="http://www.privoxy.org/user-manual/">User Manual</ulink>.
720 Now if <ulink url="http://p.p/">http://p.p/</ulink> works for you, but
721 other parts of <application>Privoxy</application>'s web interface show
722 the dummy page, your browser has cached a redirection it encountered before
723 <application>Privoxy</application> was being used. You need to clear your
724 browser's cache. Note that shift-reloading the dummy page won't help, since
725 that'll only refresh the dummy page, not the redirection that lead you there.
729 The procedure for clearing the cache varies from browser to browser. For
730 example, <application>Mozilla/Netscape</application> users would click
731 <guibutton>Edit</guibutton> --> <guibutton>Preferences</guibutton> -->
732 <guibutton>Advanced</guibutton> --> <guibutton>Cache</guibutton> and
733 then click both <quote><guibutton>Clear Memory Cache</guibutton></quote>
734 and <quote><guibutton>Clear Disk Cache</guibutton></quote>.
735 In some <application>Firefox</application> versions it's
736 <guibutton>Tools</guibutton> --> <guibutton>Options</guibutton> -->
737 <guibutton>Privacy</guibutton> --> <guibutton>Cache</guibutton> and
738 then click <quote><guibutton>Clear Cache Now</guibutton></quote>.
739 <!-- In my Firefox versions it's the Netscape way. fk 2007-11-19-->
746 <!-- ~~~~~ New section ~~~~~ -->
748 <sect1 id="configuration"><title>Configuration</title>
749 <sect2 renderas="sect3">
750 <title id="actionsfile">What exactly is an <quote>actions</quote> file?</title>
753 &my-app; utilizes the concept of <quote>
754 <ulink url="../user-manual/actions-file.html#ACTIONS">actions</ulink></quote>
755 that are used to manipulate and control web page data.
756 <ulink url="../user-manual/actions-file.html">Actions files</ulink>
757 are where these <ulink url="../user-manual/actions-file.html#ACTIONS">actions</ulink>
758 that <application>Privoxy</application> could take while processing a certain
759 request, are configured. Typically, you would define a set of default actions
760 that apply globally to all URLs, then add exceptions to these defaults where needed.
761 There is a wide array of actions available that give the user a high degree
762 of control and flexibility on how to process each and every web page.
766 Actions can be defined on a <ulink
767 url="../user-manual/actions-file.html#AF-PATTERNS">URL pattern</ulink> basis, i.e.
768 for single URLs, whole web sites, groups or parts thereof etc. Actions can also be
769 grouped together and then applied to requests matching one or more patterns.
770 There are many possible actions that might apply to any given site. As an example,
771 if you are blocking <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>
772 as one of your default actions, but need to accept cookies from a given site,
773 you would need to define an exception for this site in one of your actions
774 files, preferably in <filename>user.action</filename>.
779 <sect2 renderas="sect3" id="actionss">
780 <title>The <quote>actions</quote> concept confuses me. Please list
781 some of these <quote>actions</quote>.</title>
783 For a comprehensive discussion of the actions concept, please refer
784 to the <ulink url="../user-manual/actions-file.html">actions file
785 chapter</ulink> in the <ulink url="../user-manual/index.html">User
786 Manual</ulink>. It includes a <ulink
787 url="../user-manual/actions-file.html#ACTIONS">list of all actions</ulink>
788 and an <ulink url="../user-manual/actions-file.html#ACT-EXAMPLES">actions
789 file tutorial</ulink> to get you started.
794 <sect2 renderas="sect3">
795 <title id="actconfig">How are actions files configured? What is the easiest
796 way to do this?</title>
799 Actions files are just text files in a special syntax and can be edited
800 with a text editor. But probably the easiest way is to access
801 <application>Privoxy</application>'s user interface with your web browser
802 at <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
803 (Shortcut: <ulink url="http://p.p/">http://p.p/</ulink>) and then select
804 <quote><ulink url="http://config.privoxy.org/show-status">View &
805 change the current configuration</ulink></quote> from the menu. Note
806 that this feature must be explicitly enabled in the main config file
808 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>).
813 <sect2 renderas="sect3">
814 <title>There are several different <quote>actions</quote> files. What are
815 the differences?</title>
817 Please have a look at the <ulink url="../user-manual/actions-file.html">the actions chapter</ulink>
818 in the <ulink url="../user-manual/index.html">User Manual</ulink> for a detailed explanation.
823 <sect2 renderas="sect3" id="getupdates"><title>Where can I get updated Actions Files?</title>
825 Based on your feedback and the continuing development, updates of
826 <filename>default.action</filename> will be
827 made available from time to time on the <ulink
828 url="http://sourceforge.net/project/showfiles.php?group_id=11118">files section</ulink> of
829 our <ulink url="http://sf.net/projects/ijbswa/">project page</ulink>.
833 If you wish to receive an email notification whenever we release updates of
834 <application>Privoxy</application> or the actions file, <ulink
835 url="http://lists.sourceforge.net/lists/listinfo/ijbswa-announce/">subscribe
836 to our announce mailing list</ulink>, ijbswa-announce@lists.sourceforge.net.
841 <sect2 renderas="sect3" id="newconfig"><title>Can I use my old config files?</title>
843 The syntax and purpose of configuration files has remained roughly the
844 same throughout the 3.x series, but backwards compatibility is not guaranteed.
845 Also each release contains updated, <quote>improved</quote> versions and it is
846 therefore strongly recommended to install the newer configuration files
847 and merge back your modifications.
851 <sect2 renderas="sect3" id="difficult">
852 <title>Why is the configuration so complicated?</title>
854 <quote>Complicated</quote> is in the eye of the beholder.
857 Privoxy is currently mainly written by and for people who are already
858 familiar with the underlying concepts like regular expressions, HTTP and HTML,
859 or are willing to become familiar with them to be able to get the most
860 out of a powerful and flexible tool such as Privoxy.
863 While everybody is expected to be able to get a Privoxy default installation
864 up and running, fine-tuning requires a certain amount of background
865 information and Privoxy's documentation mainly concentrates on the
866 Privoxy-specific parts while only providing references to the rest.
869 If you or anyone you know has the skills, time and energy to
870 reduce the barrier of entry, please <link linkend="participate">get involved</link>.
874 <sect2 renderas="sect3" id="yahoo"><title>How can I make my Yahoo/Hotmail/Gmail account work?</title>
876 The default configuration shouldn't impact the usability of any of these services.
877 It may, however, make all <ulink
878 url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>
879 temporary, so that your browser will forget your
880 login credentials in between browser sessions. If you would like not to have to log
881 in manually each time you access those websites, simply turn off all cookie handling
882 for them in the <filename>user.action</filename> file. An example for yahoo might
886 <screen># Allow all cookies for Yahoo login:
888 { -<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> }
889 .login.yahoo.com</screen>
892 These kinds of sites are often quite complex and heavy with
893 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink> and
894 thus <quote>fragile</quote>. So if <emphasis>still</emphasis> a problem,
896 url="../user-manual/actions-file.html#ALIASES">alias</ulink> just for such
900 <screen># Gmail is a _fragile_ site:
902 { <literal>fragile</literal> }
904 mail.google.com</screen>
907 Be sure to flush your browser's caches whenever making these kinds of
908 changes, just to make sure the changes <quote>take</quote>.
911 Make sure the domain, host and path are appropriate as well. Your browser can
912 tell you where you are specifically and you should use that information for
913 your configuration settings. Note that above it is not referenced as
914 <literal>gmail.com</literal>, which is a valid domain name.
919 <sect2 renderas="sect3" id="configfiles"> <title>What's the difference between the
920 <quote>Cautious</quote>, <quote>Medium</quote> and <quote>Advanced</quote> defaults?</title>
922 Configuring <application>Privoxy</application> is not entirely trivial. To
923 help you get started, we provide you with three different default action
924 <quote>profiles</quote> in the web based actions file editor at <ulink
925 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>.
926 See the <ulink url="../user-manual/actions-file.html"><citetitle>User
927 Manual</citetitle></ulink> for a list of actions, and how the default
932 Where the defaults are likely to break some sites, exceptions for
933 known popular <quote>problem</quote> sites are included, but in
934 general, the more aggressive your default settings are, the more exceptions
935 you will have to make later. New users are best to start off in
936 <quote>Cautious</quote> setting. This is safest and will have the fewest
937 problems. See the <ulink
938 url="../user-manual/index.html"><citetitle>User Manual</citetitle></ulink>
939 for a more detailed discussion.
943 It should be noted that the <quote>Advanced</quote> profile (formerly known
944 as the <quote>Adventuresome</quote> profile) is more
945 aggressive, and will make use of some of
946 <application>Privoxy's</application> advanced features. Use at your own risk!
951 <sect2 renderas="sect3" id="browseconfig"> <title>Why can I change the configuration
952 with a browser? Does that not raise security issues?</title>
954 It may seem strange that regular users can edit the config files with their
955 browsers, although the whole <filename>/etc/privoxy</filename> hierarchy
956 belongs to the user <quote>privoxy</quote>, with only 644 permissions.
959 When you use the browser-based editor, <application>Privoxy</application>
960 itself is writing to the config files. Because
961 <application>Privoxy</application> is running as the user <quote>privoxy</quote>,
962 it can update its own config files.
965 If you run <application>Privoxy</application> for multiple untrusted users (e.g. in
966 a LAN) or aren't entirely in control of your own browser, you will probably want
967 to make sure that the web-based editor and remote toggle features are
968 <quote>off</quote> by setting <quote><literal><ulink
969 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>
970 0</literal></quote> and <quote><literal><ulink
971 url="../user-manual/config.html#ENABLE-REMOTE-TOGGLE">enable-remote-toggle</ulink>
972 0</literal></quote> in the <ulink url="../user-manual/config.html">main configuration file</ulink>.
975 As of &my-app; 3.0.7 these options are disabled by default.
980 <sect2 renderas="sect3">
981 <title id="filterfile">What is the <filename>default.filter</filename> file? What is a <quote>filter</quote>?</title>
983 The <ulink url="../user-manual/filter-file.html"><filename>default.filter</filename></ulink>
984 file is where <emphasis>filters</emphasis> as supplied by the developers are defined.
985 Filters are a special subset of actions that can be used to modify or
986 remove web page content or headers on the fly. Content filters can
987 be applied to <emphasis>anything</emphasis> in the page source,
988 header filters can be applied to either server or client headers.
989 Regular expressions are used to accomplish this.
992 There are a number of pre-defined filters to deal with common annoyances. The
993 filters are only defined here, to invoke them, you need to use the
995 url="../user-manual/actions-file.html#FILTER"><literal>filter</literal>
996 action</ulink> in one of the actions files. Content filtering is automatically
997 disabled for inappropriate MIME types, but if you know better than Privoxy
998 what should or should not be filtered you can filter any content you like.
1002 <emphasis>not</emphasis> be confused with <ulink
1003 url="../user-manual/actions-file.html#BLOCK"><literal>blocks</literal></ulink>, which
1004 is a completely different action, and is more typically used to block ads and
1009 If you are familiar with regular expressions, and HTML, you can look at
1010 the provided <filename>default.filter</filename> with a text editor and define
1011 your own filters. This is potentially a very powerful feature, but
1012 requires some expertise in both regular expressions and HTML/HTTP.
1013 <![%p-newstuff;[ You should
1014 place any modifications to the default filters, or any new ones you create
1015 in a separate file, such as <filename>user.filter</filename>, so they won't
1016 be overwritten during upgrades.
1017 The ability to define multiple filter files
1018 in <filename>config</filename> is a new feature as of v. 3.0.5.]]>
1022 There is no GUI editor option for this part of the configuration,
1023 but you can disable/enable the various pre-defined filters of the included
1024 <filename>default.filter</filename> file with the <ulink
1025 url="http://config.privoxy.org/show-status">web-based actions file editor</ulink>.
1026 Note that the custom actions editor must be explicitly enabled in
1027 the main config file (see <ulink
1028 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>).
1032 If you intend to develop your own filters, you might want to have a look at
1034 url="http://www.fabiankeil.de/sourcecode/pft/">Privoxy-Filter-Test</ulink>.
1039 <sect2 renderas="sect3" id="lanconfig">
1040 <title>How can I set up Privoxy to act as a proxy for my
1043 By default, <application>Privoxy</application> only responds to requests
1044 from <literal>127.0.0.1</literal> (localhost). To have it act as a server for
1045 a network, this needs to be changed in the <ulink
1046 url="../user-manual/config.html">main configuration file</ulink>. Look for
1048 url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink></literal>
1049 option, which may be commented out with a <quote>#</quote> symbol. Make sure
1050 it is uncommented, and assign it the address of the LAN gateway interface,
1051 and port number to use. Assuming your LAN address is 192.168.1.1 and you
1052 wish to run <application>Privoxy</application> on port 8118, this line
1058 listen-address 192.168.1.1:8118</screen>
1062 Save the file, and restart <application>Privoxy</application>. Configure
1063 all browsers on the network then to use this address and port number.
1067 Alternately, you can have <application>Privoxy</application> listen on
1068 all available interfaces:
1073 listen-address :8118</screen>
1077 And then use <application>Privoxy's</application>
1079 url="../user-manual/config.html#PERMIT-ACCESS">permit-access</ulink>
1080 feature to limit connections. A firewall in this situation is recommended
1085 The above steps should be the same for any TCP network, regardless of
1090 If you run <application>Privoxy</application> on a LAN with untrusted users,
1091 we recommend that you double-check the <ulink
1092 url="../user-manual/config.html#ACCESS-CONTROL">access control and security</ulink>
1099 <sect2 renderas="sect3">
1100 <title id="noseeum">Instead of ads, now I get a checkerboard pattern. I don't want to see anything.</title>
1102 The replacement for blocked images can be controlled with the <ulink
1103 url="../user-manual/actions-file.html#SET-IMAGE-BLOCKER"><literal>set-image-blocker</literal>
1104 action</ulink>. You have the choice of a checkerboard pattern, a transparent 1x1 GIF
1105 image (aka <quote>blank</quote>), or a redirect to a custom image of your choice.
1106 Note that this choice only has effect for images which are blocked as images, i.e.
1107 whose URLs match both a <literal><ulink
1108 url="../user-manual/actions-file.html#HANDLE-AS-IMAGE">handle-as-image</ulink></literal>
1109 <emphasis>and</emphasis> <literal><ulink
1110 url="../user-manual/actions-file.html#BLOCK">block</ulink></literal> action.
1113 If you want to see nothing, then change the <ulink
1114 url="../user-manual/actions-file.html#SET-IMAGE-BLOCKER"><literal>set-image-blocker</literal>
1115 action</ulink> to <quote>blank</quote>. This can be done by editing the
1116 <filename>user.action</filename> file, or through the <ulink
1117 url="http://config.privoxy.org/show-status">web-based actions file editor</ulink>.
1122 <sect2 renderas="sect3">
1123 <title id="whyseeum">Why would anybody want to see a checkerboard pattern?</title>
1125 Remember that <link linkend="whatsanad">telling which image is an ad and which
1126 isn't</link>, is an educated guess. While we hope that the standard configuration
1127 is rather smart, it will make occasional mistakes. The checkerboard image is visually
1128 decent, and it shows you where images have been blocked, which can be very
1129 helpful in case some navigation aid or otherwise innocent image was
1130 erroneously blocked. It is recommended for new users so they can
1131 <quote>see</quote> what is happening. Some people might also enjoy seeing how
1132 many banners they <emphasis>don't</emphasis> have to see.
1137 <sect2 renderas="sect3">
1138 <title id="blockedbytext">I see some images being replaced with text
1139 instead of the checkerboard image. Why and how do I get rid of this?</title>
1141 This happens when the banners are not embedded in the HTML code of the
1142 page itself, but in separate HTML (sub)documents that are loaded into (i)frames
1143 or (i)layers, and these external HTML documents are blocked. Being non-images
1144 they get replaced by a substitute HTML page rather than a substitute image,
1145 which wouldn't work out technically, since the browser expects and accepts
1146 only HTML when it has requested an HTML document.
1149 The substitute page adapts to the available space and shows itself as a
1150 miniature two-liner if loaded into small frames, or full-blown with a
1151 large red "BLOCKED" banner if space allows.
1154 If you prefer the banners to be blocked by images, you must see to it that
1155 the HTML documents in which they are embedded are not blocked. Clicking
1156 the <quote>See why</quote> link offered in the substitute page will show
1157 you which rule blocked the page. After changing the rule and un-blocking
1158 the HTML documents, the browser will try to load the actual banner images
1159 and the usual image blocking will (hopefully!) kick in.
1164 <sect2 renderas="sect3" id="srvany">
1165 <title>Can Privoxy run as a service
1166 on Win2K/NT/XP?</title>
1169 Yes. Version 3.0.5 introduces full <application>Windows</application> service
1170 functionality. See <ulink url="../user-manual/installation.html#installation-pack-win">
1171 the <citetitle>User Manual</citetitle></ulink> for details on how to install and configure
1172 <application>Privoxy</application> as a service.
1175 Earlier ]]>3.x versions could run as a system service using <command>srvany.exe</command>.
1176 See the discussion at <ulink
1177 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>,
1178 for details, and a sample configuration.
1183 <sect2 renderas="sect3" id="otherproxy">
1184 <title>How can I make Privoxy work with other proxies?</title>
1186 This can be done and is often useful to combine the benefits of
1187 <application>Privoxy</application> with those of a another proxy,
1188 for example to cache content.
1190 url="../user-manual/config.html#FORWARDING">forwarding chapter</ulink>
1191 in the <ulink url="../user-manual/index.html">User Manual</ulink> which
1192 describes how to do this. If you intend to use Privoxy with Tor,
1193 please also have a look at
1194 <link linkend="TOR">How do I use Privoxy together with Tor</link>.
1198 <sect2 renderas="sect3" id="port-80">
1199 <title>Can I just set Privoxy to use port 80
1200 and thus avoid individual browser configuration?</title>
1203 No, its more complicated than that. This only works with special kinds
1204 of proxies known as <quote>intercepting</quote> proxies
1205 (<link linkend="INTERCEPTING">see below</link>).
1210 <sect2 renderas="sect3" id="transparent">
1211 <title>Can Privoxy run as a <quote>transparent
1212 </quote> proxy?</title>
1214 The whole idea of Privoxy is to modify client requests
1215 and server responses in all sorts of ways and therefore
1216 it's not a transparent proxy as described in
1217 <ulink url="http://tools.ietf.org/html/rfc2616">RFC 2616</ulink>.
1220 However, some people say <quote>transparent proxy</quote> when they
1221 mean <quote>intercepting proxy</quote>. If you are one of them,
1222 please read the <link linkend="INTERCEPTING">next entry</link>.
1227 <sect2 renderas="sect3" id="intercepting">
1228 <title>Can Privoxy run as a <quote>intercepting</quote> proxy?</title>
1230 <application>Privoxy</application> can't intercept traffic itself,
1231 but it can handle requests that where intercepted and redirected
1232 with a packet filter (like <application>PF</application> or
1233 <application>iptables</application>), as long as the <literal>Host</literal>
1237 As the <literal>Host</literal> header is required by HTTP/1.1 and as most
1238 web sites rely on it anyway, this limitation shouldn't be a problem.
1241 Please refer to your packet filter's documentation to learn how to
1242 intercept and redirect traffic into <application>Privoxy</application>.
1243 Afterward you just have to configure <application>Privoxy</application> to
1244 <ulink url="../user-manual/config.html#ACCEPT-INTERCEPTED-REQUESTS">accept
1245 intercepted requests</ulink>.
1250 <sect2 renderas="sect3" id="outlook">
1251 <title>How can I configure Privoxy for use with Outlook?</title>
1253 Versions of <application>Outlook</application> prior to Office 2007, use
1254 <application>Internet Explorer</application> components to both render HTML,
1255 and fetch any HTTP requests that may be embedded in an HTML email. So however
1256 you have <application>Privoxy</application> configured to work with IE, this
1257 configuration should automatically be shared, at least with older version of
1261 Starting with Office 2007, Microsoft is instead using the MS-Word rendering
1262 engine with Outlook. It is unknown whether this can be configured to use a
1264 <!-- FIXME HB 2009-02-15 -->
1268 <sect2 renderas="sect3" id="outlook-more">
1269 <title>How can I have separate rules just for HTML mail?</title>
1271 The short answer is, you can't. <application>Privoxy</application> has no way
1272 of knowing which particular application makes a request, so there is no way to
1273 distinguish between web pages and HTML mail.
1274 <application>Privoxy</application> just blindly proxies all requests. In the
1275 case of <application>Outlook Express</application> (see above), OE uses
1276 IE anyway, and there is no way for <application>Privoxy</application> to ever
1277 be able to distinguish between them (nor could any other proxy type application for
1281 For a good discussion of some of the issues involved (including privacy and
1282 security issues), see
1283 <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>.
1287 <sect2 renderas="sect3" id="sneaky-cookies">
1288 <title>I sometimes notice cookies sneaking through. How?</title>
1291 url="http://en.wikipedia.org/wiki/Browser_cookie">Cookies</ulink> can be
1292 set in several ways. The classic method is via the
1293 <literal>Set-Cookie</literal> HTTP header. This is straightforward, and an
1294 easy one to manipulate, such as the &my-app; concept of
1295 <ulink url="../user-manual/actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</ulink>.
1296 There is also the possibility of using
1297 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink> to
1298 set cookies (&my-app; calls these <literal>content-cookies</literal>). This
1299 is trickier because the syntax can vary widely, and thus requires a certain
1300 amount of guesswork. It is not realistic to catch all of these short of
1301 disabling Javascript, which would break many sites. And lastly, if the
1302 cookies are embedded in a HTTPS/SSL secure session via Javascript, they are beyond
1303 <application>Privoxy's</application> reach.
1306 All in all, &my-app; can help manage cookies in general, can help minimize
1307 the loss of privacy posed by cookies, but can't realistically stop all
1312 <sect2 renderas="sect3" id="evil-cookies">
1313 <title>Are all cookies bad? Why?</title>
1315 No, in fact there are many beneficial uses of
1317 url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>. Cookies are just a
1318 method that browsers can use to store data between pages, or between browser
1319 sessions. Sometimes there is a good reason for this, and the user's life is a
1320 bit easier as a result. But there is a long history of some websites taking
1321 advantage of this layer of trust, and using the data they glean from you and
1322 your browsing habits for their own purposes, and maybe to your potential
1323 detriment. Such sites are using you and storing their data on your system.
1324 That is why the privacy conscious watch from whom those cookies come, and why
1325 they really <emphasis>need</emphasis> to be there.
1329 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">Wikipedia cookie
1330 definition</ulink> for more.
1334 <sect2 renderas="sect3" id="allow-cookies">
1335 <title>How can I allow permanent cookies for my trusted sites?</title>
1338 There are several actions that relate to cookies. The default behavior is to
1339 allow only <quote>session cookies</quote>, which means the cookies only last
1340 for the current browser session. This eliminates most kinds of abuse related
1341 to cookies. But there may be cases where you want cookies to last.
1344 To disable all cookie actions, so that cookies are allowed unrestricted,
1345 both in and out, for <literal>example.com</literal>:
1349 { -crunch-incoming-cookies -crunch-outgoing-cookies -session-cookies-only -filter{content-cookies} }
1350 .example.com</screen>
1353 Place the above in <filename>user.action</filename>. Note that some of these may
1354 be off by default anyway, so this might be redundant, but there is no harm
1355 being explicit in what you want to happen. <filename>user.action</filename>
1356 includes an alias for this situation, called
1357 <literal>allow-all-cookies</literal>.
1361 <sect2 renderas="sect3" id="multiples">
1362 <title>Can I have separate configurations for different users?</title>
1364 Each instance of <application>Privoxy</application> has its own
1365 configuration, including such attributes as the TCP port that it listens on.
1366 What you can do is run multiple instances of <application>Privoxy</application>, each with
1368 <ulink url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink>
1369 configuration setting, and configuration path, and then
1370 each of these can have their own configurations. Think of it as per-port
1374 Simple enough for a few users, but for large installations, consider having
1375 groups of users that might share like configurations.
1379 <sect2 renderas="sect3" id="whitelists">
1380 <title>Can I set-up Privoxy as a whitelist of
1381 <quote>good</quote> sites?</title>
1383 Sure. There are a couple of things you can do for simple white-listing.
1384 Here's one real easy one:
1387 ############################################################
1389 ############################################################
1390 { <ulink url="../user-manual/actions-file.html#BLOCK">+block</ulink> }
1391 / # Block *all* URLs
1393 ############################################################
1395 ############################################################
1396 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> }
1399 games.example.com</screen>
1401 This allows access to only those three sites by first blocking all URLs, and
1402 then subsequently allowing three specific exceptions.
1405 Another approach is <application>Privoxy's</application>
1406 <literal>trustfile</literal> concept, which incorporates the notion of
1407 <quote>trusted referrers</quote>. See the <ulink
1408 url="../user-manual/config.html#TRUSTFILE">Trust documentation</ulink>
1412 These are fairly simple approaches and are not completely foolproof. There
1413 are various other configuration options that should be disabled (described
1414 elsewhere here and in <ulink url="../user-manual/">the User Manual</ulink>)
1415 so that users can't modify their own configuration and easily circumvent the
1420 <sect2 renderas="sect3" id="no-adblock">
1421 <title>How can I turn off ad-blocking?</title>
1423 Ad blocking is achieved through a complex application of various &my-app;
1424 <ulink url="../user-manual/actions-file.html">actions</ulink>. These
1425 actions are deployed against simple images, banners, flash animations,
1426 text pages, JavaScript, pop-ups and pop-unders, etc., so its not as simple as
1427 just turning one or two actions off. The various actions that make up
1428 &my-app; ad blocking are hard-coded into the default configuration files. It
1429 has been assumed that everyone using &my-app; is interested in this
1433 If you want to do without this, there are several approaches you can take:
1434 You can manually undo the many block rules in
1435 <filename>default.action</filename>. Or even easier, just create your own
1436 <filename>default.action</filename> file from scratch without the many ad
1437 blocking rules, and corresponding exceptions. Or lastly, if you are not
1438 concerned about the additional blocks that are done for privacy reasons, you
1439 can very easily over-ride <emphasis>all</emphasis> blocking with the
1440 following very simple rule in your <filename>user.action</filename>:
1444 # Unblock everybody, everywhere
1445 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> }
1446 / # UN-Block *all* URLs</screen>
1449 Or even a more comprehensive reversing of various ad related actions:
1453 # Unblock everybody, everywhere, and turn off appropriate filtering, etc
1454 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> \
1455 <ulink url="../user-manual/actions-file.html#FILTER-BANNERS-BY-SIZE">-filter{banners-by-size}</ulink> \
1456 <ulink url="../user-manual/actions-file.html#FILTER-BANNERS-BY-LINK">-filter{banners-by-link}</ulink> \
1457 <literal>allow-popups</literal> \
1459 / # UN-Block *all* URLs and allow ads</screen>
1462 This last <quote>action</quote> in this compound statement,
1463 <literal>allow-popups</literal>, is an <ulink
1464 url="../user-manual/actions-file.html#ALIASES">alias</ulink> that disables
1465 various pop-up blocking features.
1469 <sect2 renderas="sect3" id="templates">
1470 <title>How can I have custom template pages, like the
1471 <emphasis>BLOCKED</emphasis> page?</title>
1473 &my-app; <quote>templates</quote> are specialized text files utilized by
1474 &my-app; for various purposes and can easily be modified using any text
1475 editor. All the template pages are installed in a sub-directory appropriately
1476 named: <filename>templates</filename>. Knowing something about HTML syntax
1477 will of course be helpful.
1480 Be forewarned that the default templates are subject to being overwritten
1481 during upgrades. You can, however, create completely new templates,
1482 place them in another directory and specify the alternate path in the main
1483 <filename>config</filename>. For details, have a look at the <ulink
1484 url="../user-manual/config.html#templdir">templdir</ulink> option.
1488 <sect2 renderas="sect3" id="blockall">
1489 <title>How can I remove the <quote>Go There Anyway</quote> link from
1490 the <emphasis>BLOCKED</emphasis> page?</title>
1492 There is more than one way to do it (although Perl is not involved).
1495 Editing the BLOCKED template page (see above) may dissuade some users, but
1496 this method is easily circumvented. Where you need this level of control, you
1497 might want to build &my-app; from source, and disable various features that are
1498 available as compile-time options. You should
1499 <command>configure</command> the sources as follows:
1503 ./configure --disable-toggle --disable-editor --disable-force</screen>
1506 This will create an executable with hard-coded security features so that
1507 &my-app; does not allow easy bypassing of blocked sites, or changing the
1508 current configuration via any connected user's web browser.
1511 Finally, all of these features can also be toggled on/off via options in
1512 <application>Privoxy's</application> main <ulink
1513 url="../user-manual/config.html#ACCESS-CONTROL">config</ulink> file which
1514 means you don't have to recompile anything.
1520 <!-- ~ End section ~ -->
1523 <!-- ~~~~~ New section ~~~~~ -->
1525 <sect1 id="misc"><title>Miscellaneous</title>
1527 <sect2 renderas="sect3">
1528 <title id="slowsme">How much does Privoxy slow my browsing down? This
1529 has to add extra time to browsing.</title>
1531 How much of an impact depends on many things, including the CPU of the host
1532 system, how aggressive the configuration is, which specific actions are being triggered,
1533 the size of the page, the bandwidth of the connection, etc.
1536 Overall, it should not slow you down any in real terms, and may actually help
1537 speed things up since ads, banners and other junk are not typically being
1538 retrieved and displayed. The actual processing time required by
1539 <application>Privoxy</application> itself for each page, is relatively small
1540 in the overall scheme of things, and happens very quickly. This is typically
1541 more than offset by time saved not downloading and rendering ad images and
1542 other junk content (if ad blocking is being used).
1546 <quote>Filtering</quote> content via the <literal><ulink
1547 url="../user-manual/actions-file.html#FILTER">filter</ulink></literal> or
1549 url="../user-manual/actions-file.html#DEANIMATE-GIFS">deanimate-gifs</ulink></literal>
1550 actions may cause a perceived slowdown, since the entire document
1551 needs to be buffered before displaying. And on very large documents,
1552 filtering may have some measurable impact. How much depends on the page size,
1553 the actual definition of the filter(s), etc. See below. Most other actions
1554 have little to no impact on speed.
1557 Also, when filtering is enabled but zlib support isn't available, compression
1558 is often disabled (see <ulink
1559 url="../user-manual/actions-file.html#PREVENT-COMPRESSION">prevent-compression</ulink>).
1560 This can have an impact on speed as well, although it's probably smaller than
1561 you might think. Again, the page size, etc. will determine how much of an impact.
1567 <sect2 renderas="sect3" id="loadingtimes"><title>I notice considerable
1568 delays in page requests. What's wrong?</title>
1570 If you use any <literal><ulink
1571 url="../user-manual/actions-file.html#FILTER">filter</ulink></literal> action,
1572 such as filtering banners by size, web-bugs etc, or the <literal><ulink
1573 url="../user-manual/actions-file.html#DEANIMATE-GIFS">deanimate-gifs</ulink></literal>
1574 action, the entire document must be loaded into memory in order for the filtering
1575 mechanism to work, and nothing is sent to the browser during this time.
1578 The loading time typically does not really change much in real numbers, but
1579 the feeling is different, because most browsers are able to start rendering
1580 incomplete content, giving the user a feeling of "it works". This effect is
1581 more noticeable on slower dialup connections. Extremely large documents
1582 may have some impact on the time to load the page where there is filtering
1583 being done. But overall, the difference should be very minimal. If there is a
1584 big impact, then probably some other situation is contributing (like
1585 anti-virus software).
1588 Filtering is automatically disabled for inappropriate MIME types. But note
1589 that if the web server mis-reports the MIME type, then content that should
1590 not be filtered, could be. <application>Privoxy</application> only knows how
1591 to differentiate filterable content because of the MIME type as reported by
1592 the server, or because of some configuration setting that enables/disables
1597 <sect2 renderas="sect3" id="configurl"><title>What are "http://config.privoxy.org/" and
1598 "http://p.p/"?</title>
1600 <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink> is the
1601 address of <application>Privoxy</application>'s built-in user interface, and
1602 <ulink url="http://p.p/">http://p.p/</ulink> is a shortcut for it.
1605 Since <application>Privoxy</application> sits between your web browser and the Internet,
1606 it can simply intercept requests for these addresses and answer them with its built-in
1607 <quote>web server</quote>.
1610 This also makes for a good test for your browser configuration: If entering the
1611 URL <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
1612 takes you to a page saying <quote>This is Privoxy ...</quote>, everything is OK.
1613 If you get a page saying <quote>Privoxy is not working</quote> instead, then
1614 your browser didn't use <application>Privoxy</application> for the request,
1615 hence it could not be intercepted, and you have accessed the <emphasis>real</emphasis>
1616 web site at config.privoxy.org.
1622 out of date 09/02/06 HB
1623 <sect2 renderas="sect3" id="blocklist"><title>Do you still maintain the blocklists?</title>
1625 No. The patterns for blocking now reside (among other things) in the <ulink
1626 url="../user-manual/actions-file.html">actions files</ulink>, which are
1627 actively maintained instead. See next question ...
1631 <sect2 renderas="sect3" id="newads"><title>How can I submit new ads, or report
1634 Please see the <link linkend="contact">Contact section</link> for
1635 various ways to interact with the developers.
1640 <sect2 renderas="sect3" id="newads2"><title>If I do submit missed ads, will
1641 they be included in future updates?</title>
1643 Whether such submissions are eventually included in the
1644 <filename>default.action</filename> configuration file depends on how
1645 significant the issue is. We of course want to address any potential
1646 problem with major, high-profile sites such as <citetitle>Google</citetitle>,
1647 <citetitle>Yahoo</citetitle>, etc. Any site with global or regional reach,
1648 has a good chance of being a candidate. But at the other end of the spectrum
1649 are any number of smaller, low-profile sites such as for local clubs or
1650 schools. Since their reach and impact are much less, they are best handled by
1651 inclusion in the user's <filename>user.action</filename>, and thus would be
1652 unlikely to be included.
1658 <sect2 renderas="sect3" id="noonecares"><title>Why doesn't anyone answer my support
1661 Rest assured that it has been read and considered. Why it is not answered,
1662 could be for various reasons, including no one has a good answer for it, no
1663 one has had time to yet investigate it thoroughly, it has been reported
1664 numerous times already, or because not enough information was provided to help
1665 us help you. Your efforts are not wasted, and we do appreciate them.
1671 <sect2 renderas="sect3" id="ip"><title>How can I hide my IP address?</title>
1673 If you run both the browser and &my-app; locally, you cannot hide your IP
1674 address with <application>Privoxy</application> or ultimately any other
1675 software alone. The server needs to know your IP address so that it knows
1676 where to send the responses back.
1679 There are many publicly usable "anonymous" proxies out there, which
1680 provide a further level of indirection between you and the web server.
1683 However, these proxies are called "anonymous" because you don't need
1684 to authenticate, not because they would offer any real anonymity.
1685 Most of them will log your IP address and make it available to the
1686 authorities in case you violate the law of the country they run in. In fact
1687 you can't even rule out that some of them only exist to *collect* information
1688 on (those suspicious) people with a more than average preference for privacy.
1691 If you want to hide your IP address from most adversaries,
1692 you should consider chaining <application>Privoxy</application>
1693 with <ulink url="https://www.torproject.org/">Tor</ulink>.
1694 The configuration details can be found in
1695 <ulink url="#TOR">How do I use <application>Privoxy</application> together
1696 with <application>Tor</application> section</ulink>
1701 <sect2 renderas="sect3">
1702 <title id="anonforsure">Can Privoxy guarantee I am anonymous?</title>
1704 No. Your chances of remaining anonymous are improved, but unless you
1705 <ulink url="#TOR">chain <application>Privoxy</application> with <application>Tor</application></ulink>
1706 or a similar proxy and know what you're doing when it comes to configuring
1707 the rest of your system, you should assume that everything you do
1708 on the Web can be traced back to you.
1711 <application>Privoxy</application> can remove various information about you,
1712 and allows <emphasis>you</emphasis> more freedom to decide which sites
1713 you can trust, and what details you want to reveal. But it neither
1714 hides your IP address, nor can it guarantee that the rest of the system
1715 behaves correctly. There are several possibilities how a web sites can find
1716 out who you are, even if you are using a strict <application>Privoxy</application>
1717 configuration and chained it with <application>Tor</application>.
1720 Most of <application>Privoxy's</application> privacy-enhancing features can be easily subverted
1721 by an insecure browser configuration, therefore you should use a browser that can
1722 be configured to only execute code from trusted sites, and be careful which sites you trust.
1723 For example there is no point in having <application>Privoxy</application>
1724 modify the User-Agent header, if websites can get all the information they want
1725 through JavaScript, ActiveX, Flash, Java etc.
1728 A few browsers disclose the user's email address in certain situations, such
1729 as when transferring a file by FTP. <application>Privoxy</application>
1730 does not filter FTP. If you need this feature, or are concerned about the
1731 mail handler of your browser disclosing your email address, you might
1732 consider products such as <application>NSClean</application>.
1735 Browsers available only as binaries could use non-standard headers to give
1736 out any information they can have access to: see the manufacturer's license
1737 agreement. It's impossible to anticipate and prevent every breach of privacy
1738 that might occur. The professionally paranoid prefer browsers available as
1739 source code, because anticipating their behavior is easier. Trust the source,
1745 <sect2 renderas="sect3">
1746 <title id="proxytest">A test site says I am not using a Proxy.</title>
1748 Good! Actually, they are probably testing for some other kinds of proxies.
1749 Hiding yourself completely would require additional steps.
1753 <sect2 renderas="sect3" id="tor"><title>How do I use Privoxy
1754 together with Tor?</title>
1756 Before you configure <application>Privoxy</application> to use
1757 <ulink url="https://www.torproject.org/">Tor</ulink>,
1758 please follow the <citetitle>User Manual</citetitle> chapters
1759 <ulink url="../user-manual/installation.html">2. Installation</ulink> and
1760 <ulink url="../user-manual/startup.html">5. Startup</ulink> to make sure
1761 <application>Privoxy</application> itself is setup correctly.
1764 If it is, refer to <ulink url="https://www.torproject.org/documentation.html">Tor's
1765 extensive documentation</ulink> to learn how to install <application>Tor</application>,
1766 and make sure <application>Tor</application>'s logfile says that
1767 <quote>Tor has successfully opened a circuit</quote> and it
1768 <quote>looks like client functionality is working</quote>.
1771 If either <application>Tor</application> or <application>Privoxy</application>
1772 isn't working, their combination most likely will neither. Testing them on their
1773 own will also help you to direct problem reports to the right audience.
1774 If <application>Privoxy</application> isn't working, don't bother the
1775 <application>Tor</application> developers. If <application>Tor</application>
1776 isn't working, don't send bug reports to the <application>Privoxy</application> Team.
1779 If you verified that <application>Privoxy</application> and <application>Tor</application>
1780 are working, it is time to connect them. As far as <application>Privoxy</application>
1781 is concerned, <application>Tor</application> is just another proxy that can be reached
1782 by socks4, socks4a and socks5. Most likely you are interested in <application>Tor</application>
1783 to increase your anonymity level, therefore you should use socks5, to make sure DNS
1784 requests are done through <application>Tor</application> and thus invisible to your
1785 local network. Using socks4a would work too, but with socks5 you get more precise error
1790 <application>Privoxy's</application>
1791 <ulink url="../user-manual/config.html">main configuration file</ulink>
1792 is already prepared for <application>Tor</application>, if you are using a
1793 default <application>Tor</application> configuration and run it on the same
1794 system as &my-app;, you just have to edit the
1795 <ulink url="../user-manual/config.html#FORWARDING">forwarding section</ulink>
1796 and uncomment the line:
1800 # forward-socks5t / 127.0.0.1:9050 .
1804 Note that if you got Tor through one of the bundles, you may
1805 have to change the port from 9050 to 9150 (or even another one).
1806 For details, please check the documentation on the
1807 <ulink url="https://torproject.org/">Tor website</ulink>.
1811 This is enough to reach the Internet, but additionally you might want to
1812 uncomment the following forward rules, to make sure your local network is still
1813 reachable through Privoxy:
1817 # forward 192.168.*.*/ .
1818 # forward 10.*.*.*/ .
1819 # forward 127.*.*.*/ .
1823 Unencrypted connections to systems in these address ranges will
1824 be as (un)secure as the local network is, but the alternative is
1825 that your browser can't reach the network at all. Then again,
1826 that may actually be desired and if you don't know for sure
1827 that your browser has to be able to reach the local network,
1828 there's no reason to allow it.
1831 If you want your browser to be able to reach servers in your local
1832 network by using their names, you will need additional exceptions
1833 that look like this:
1837 # forward localhost/ .
1841 Save the modified configuration file and open
1842 <ulink url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
1843 in your browser, confirm that <application>Privoxy</application> has reloaded its configuration
1844 and that there are no other forward lines, unless you know that you need them. If everything looks good,
1846 <ulink url="https://wiki.torproject.org/noreply/TheOnionRouter/TorFAQ#IsMyConnectionPrivate">Tor
1847 Faq 4.2</ulink> to learn how to verify that you are really using <application>Tor</application>.
1850 Afterward, please take the time to at least skim through the rest
1851 of <application>Tor's</application> documentation. Make sure you understand
1852 what <application>Tor</application> does, why it is no replacement for
1853 application level security, and why you probably don't want to
1854 use it for unencrypted logins.
1858 <sect2 renderas="sect3">
1859 <title id="sitebreak">Might some things break because header information or
1860 content is being altered?</title>
1863 Definitely. It is common for sites to use browser type, browser version,
1864 HTTP header content, and various other techniques in order to dynamically
1865 decide what to display and how to display it. What you see, and what I see,
1866 might be very different. There are many, many ways that this can be handled,
1867 so having hard and fast rules, is tricky.
1871 The <quote>User-Agent</quote> is sometimes used in this way to identify
1872 the browser, and adjust content accordingly.
1876 Also, different browsers use different encodings of non-English
1877 characters, certain web servers convert pages on-the-fly according to the
1878 User Agent header. Giving a <quote>User Agent</quote> with the wrong
1879 operating system or browser manufacturer causes some sites in these languages
1880 to be garbled; Surfers to Eastern European sites should change it to
1881 something closer. And then some page access counters work by looking at the
1882 <quote>Referer</quote> header; they may fail or break if unavailable. The
1883 weather maps of Intellicast have been blocked by their server when no
1884 <quote>Referer</quote> or cookie is provided, is another example. (But you
1885 can forge both headers without giving information away). There are
1886 many other ways things can go wrong when trying to fool a web server. The
1887 results of which could inadvertently cause pages to load incorrectly,
1888 partially, or even not at all. And there may be no obvious clues as to just
1889 what went wrong, or why. Nowhere will there be a message that says
1890 <quote><emphasis>Turn off <literal>fast-redirects</literal> or else!</emphasis>
1895 Similar thoughts apply to modifying JavaScript, and, to a lesser degree,
1900 If you have problems with a site, you will have to adjust your configuration
1901 accordingly. Cookies are probably the most likely adjustment that may
1902 be required, but by no means the only one.
1908 <sect2 renderas="sect3">
1909 <title id="caching">Can Privoxy act as a <quote>caching</quote> proxy to
1910 speed up web browsing?</title>
1912 No, it does not have this ability at all. You want something like
1913 <ulink url="http://www.squid-cache.org/">Squid</ulink> or
1914 <ulink url="http://www.pps.jussieu.fr/~jch/software/polipo/">Polipo</ulink> for this.
1915 And, yes, before you ask, <application>Privoxy</application> can co-exist
1916 with other kinds of proxies like <application>Squid</application>.
1917 See the <ulink url="../user-manual/config.html#FORWARDING">forwarding
1918 chapter</ulink> in the <ulink url="../user-manual/index.html">user
1919 manual</ulink> for details.
1923 <sect2 renderas="sect3">
1924 <title id="firewall">What about as a firewall? Can Privoxy protect me?</title>
1926 Not in the way you mean, or in the way some firewall vendors claim they can.
1927 <application>Privoxy</application> can help protect your privacy, but can't
1928 protect your system from intrusion attempts. It is, of course, perfectly possible
1929 to use <emphasis>both</emphasis>.
1933 <sect2 renderas="sect3">
1934 <title id="wasted">I have large empty spaces / a checkerboard pattern now where
1935 ads used to be. Why?</title>
1937 It is technically possible to eliminate banners and ads in a way that frees
1938 their allocated page space. This could easily be done by blocking with
1939 <application>Privoxy's</application> filters,
1940 and eliminating the <emphasis>entire</emphasis> image references from the
1944 But, this would consume considerably more CPU resources (IOW, slow things
1945 down), would likely destroy the layout of some web pages which rely on the
1946 banners utilizing a certain amount of page space, and might fail in other
1947 cases, where the screen space is reserved (e.g. by HTML tables for instance).
1948 Also, making ads and banners disappear without any trace complicates
1949 troubleshooting, and would sooner or later be problematic.
1952 The better alternative is to instead let them stay, and block the resulting
1953 requests for the banners themselves as is now the case. This leaves either
1954 empty space, or the familiar checkerboard pattern.
1957 So the developers won't support this in the default configuration, but you
1958 can of course define appropriate filters yourself to achieve this.
1962 <sect2 renderas="sect3">
1963 <title id="ssl">How can Privoxy filter Secure (HTTPS) URLs?</title>
1965 Since secure HTTP connections are encrypted SSL sessions between your browser
1966 and the secure site, and are meant to be reliably <emphasis>secure</emphasis>,
1967 there is little that <application>Privoxy</application> can do but hand the raw
1968 gibberish data though from one end to the other unprocessed.
1971 The only exception to this is blocking by host patterns, as the client needs
1972 to tell <application>Privoxy</application> the name of the remote server,
1973 so that <application>Privoxy</application> can establish the connection.
1974 If that name matches a host-only pattern, the connection will be blocked.
1977 As far as ad blocking is concerned, this is less of a restriction than it may
1978 seem, since ad sources are often identifiable by the host name, and often
1979 the banners to be placed in an encrypted page come unencrypted nonetheless
1980 for efficiency reasons, which exposes them to the full power of
1981 <application>Privoxy</application>'s ad blocking.
1984 <quote>Content cookies</quote> (those that are embedded in the actual HTML or
1985 JS page content, see <literal><ulink
1986 url="../user-manual/actions-file.html#FILTER-CONTENT-COOKIES">filter{content-cookies}</ulink></literal>),
1987 in an SSL transaction will be impossible to block under these conditions.
1988 Fortunately, this does not seem to be a very common scenario since most
1989 cookies come by traditional means.
1994 <sect2 renderas="sect3">
1995 <title id="secure">Privoxy runs as a <quote>server</quote>. How
1996 secure is it? Do I need to take any special precautions?</title>
1998 On Unix-like systems, <application>Privoxy</application> can run as a non-privileged
1999 user, which is how we recommend it be run. Also, by default
2000 <application>Privoxy</application> listens to requests from <quote>localhost</quote>
2004 The server aspect of <application>Privoxy</application> is not itself directly
2005 exposed to the Internet in this configuration. If you want to have
2006 <application>Privoxy</application> serve as a LAN proxy, this will have to
2007 be opened up to allow for LAN requests. In this case, we'd recommend
2008 you specify only the LAN gateway address, e.g. 192.168.1.1, in the main
2009 <application>Privoxy</application> configuration file and check all <ulink
2010 url="../user-manual/config.html#ACCESS-CONTROL">access control and security
2011 options</ulink>. All LAN hosts can then use this as their proxy address
2012 in the browser proxy configuration, but <application>Privoxy</application>
2013 will not listen on any external interfaces. ACLs can be defined in addition,
2014 and using a firewall is always good too. Better safe than sorry.
2019 <sect2 renderas="sect3" id="turnoff">
2020 <title>Can I temporarily disable Privoxy?</title>
2022 &my-app; doesn't have a transparent proxy mode,
2023 but you can toggle off blocking and content filtering.
2026 The easiest way to do that is to point your browser
2027 to the remote toggle URL: <ulink
2028 url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>.
2031 See the <ulink url="../user-manual/appendix.html#BOOKMARKLETS">Bookmarklets section</ulink>
2032 of the <citetitle>User Manual</citetitle> for an easy way to access this
2033 feature. Note that this is a feature that may need to be enabled in the main
2034 <filename>config</filename> file.
2039 <sect2 renderas="sect3" id="reallyoff">
2040 <title>When <quote>disabled</quote> is Privoxy totally
2041 out of the picture?</title>
2043 No, this just means all optional filtering and actions are disabled.
2044 <application>Privoxy</application> is still acting as a proxy, but just
2045 doing less of the things that <application>Privoxy</application> would
2046 normally be expected to do. It is still a <quote>middle-man</quote> in
2047 the interaction between your browser and web sites. See below to bypass
2052 <sect2 renderas="sect3" id="turnoff2">
2053 <title>How can I tell Privoxy to totally ignore certain sites?</title>
2055 Bypassing a proxy, or proxying based on arbitrary criteria, is purely a browser
2056 configuration issue, not a &my-app; issue. Modern browsers typically do have
2057 settings for not proxying certain sites. Check your browser's help files.
2062 <sect2 renderas="sect3" id="crunch">
2063 <title>My logs show Privoxy <quote>crunches</quote>
2064 ads, but also its own internal CGI pages. What is a <quote>crunch</quote>?</title>
2066 A <quote>crunch</quote> simply means <application>Privoxy</application> intercepted
2067 <emphasis>something</emphasis>, nothing more. Often this is indeed ads or
2068 banners, but <application>Privoxy</application> uses the same mechanism for
2069 trapping requests for its own internal pages. For instance, a request for
2070 <application>Privoxy's</application> configuration page at: <ulink
2071 url="http://config.privoxy.org">http://config.privoxy.org</ulink>, is
2072 intercepted (i.e. it does not go out to the 'net), and the familiar CGI
2073 configuration is returned to the browser, and the log consequently will show
2074 a <quote>crunch</quote>.
2077 Since version 3.0.7, Privoxy will also log the crunch reason.
2078 If you are using an older version you might want to upgrade.
2082 <sect2 renderas="sect3" id="downloads">
2083 <title>Can Privoxy effect files that I download
2084 from a webserver? FTP server?</title>
2086 From the webserver's perspective, there is no difference between
2087 viewing a document (i.e. a page), and downloading a file. The same is true of
2088 <application>Privoxy</application>. If there is a match for a <literal><ulink
2089 url="../user-manual/actions-file.html#BLOCK">block</ulink></literal> pattern,
2090 it will still be blocked, and of course this is obvious.
2093 Filtering is potentially more of a concern since the results are not always
2094 so obvious, and the effects of filtering are there whether the file is simply
2095 viewed, or downloaded. And potentially whether the content is some obnoxious
2096 advertisement, or Mr. Jimmy's latest/greatest source code jewel. Of course,
2097 one of these presumably is <quote>bad</quote> content that we don't want, and
2098 the other is <quote>good</quote> content that we do want.
2099 <application>Privoxy</application> is blind to the differences, and can only
2100 distinguish <quote>good from bad</quote> by the configuration parameters
2101 <emphasis>we</emphasis> give it.
2104 <application>Privoxy</application> knows the differences in files according
2105 to the <quote>Content Type</quote> as reported by the webserver. If this is
2106 reported accurately (e.g. <quote>application/zip</quote> for a zip archive),
2107 then <application>Privoxy</application> knows to ignore these where
2108 appropriate. <application>Privoxy</application> potentially can filter HTML
2109 as well as plain text documents, subject to configuration parameters of
2110 course. Also, documents that are of an unknown type (generally assumed to be
2111 <quote>text/plain</quote>) can be filtered, as will those that might be
2112 incorrectly reported by the webserver. If such a file is a downloaded file
2113 that is intended to be saved to disk, then any content that might have been
2114 altered by filtering, will be saved too, for these (probably rare) cases.
2117 Note that versions later than 3.0.2 do NOT filter document types reported as
2118 <quote>text/plain</quote>. Prior to this, <application>Privoxy</application>
2119 did filter this document type.
2122 In short, filtering is <quote>ON</quote> if a) the content type as reported
2123 by the webserver is appropriate <emphasis>and</emphasis> b) the configuration
2124 allows it (or at least does not disallow it). That's it. There is no magic
2125 cookie anywhere to say this is <quote>good</quote> and this is
2126 <quote>bad</quote>. It's the configuration that lets it all happen or not.
2129 If you download text files, you probably do not want these to be filtered,
2130 particularly if the content is source code, or other critical content. Source
2131 code sometimes might be mistaken for Javascript (i.e. the kind that might
2132 open a pop-up window). It is recommended to turn off filtering for download
2133 sites (particularly if the content may be plain text files and you are using
2134 version 3.0.2 or earlier) in your <filename>user.action</filename> file. And
2135 also, for any site or page where making <emphasis>any</emphasis> changes at
2136 all to the content is to be avoided.
2139 <application>Privoxy</application> does not do FTP at all, only HTTP
2140 and HTTPS (SSL) protocols.
2144 <sect2 renderas="sect3" id="downloads2">
2145 <title>I just downloaded a Perl script, and Privoxy
2146 altered it! Yikes, what is wrong!</title>
2152 <sect2 renderas="sect3" id="hostsfile">
2153 <title>Should I continue to use a <quote>HOSTS</quote> file for ad-blocking?</title>
2155 One time-tested technique to defeat common ads is to trick the local DNS
2156 system by giving a phony IP address for the ad generator in the local
2157 <filename>HOSTS</filename> file, typically using <literal>127.0.0.1</literal>, aka
2158 <literal>localhost</literal>. This effectively blocks the ad.
2161 There is no reason to use this technique in conjunction with
2162 <application>Privoxy</application>. <application>Privoxy</application>
2163 does essentially the same thing, much more elegantly and with much more
2164 flexibility. A large <filename>HOSTS</filename> file, in fact, not only
2165 duplicates effort, but may get in the way and seriously slow down your system.
2166 It is recommended to remove such entries from your <filename>HOSTS</filename> file. If you think
2167 your hosts list is neglected by <application>Privoxy's </application>
2168 configuration, consider adding your list to your <filename>user.action</filename> file:
2175 ads.galore.example.com
2176 etc.example.com</screen>
2180 <sect2 renderas="sect3" id="seealso">
2181 <title>Where can I find more information about Privoxy
2182 and related issues?</title>
2183 <!-- Include seealso.sgml boilerplate: -->
2185 <!-- end boilerplate -->
2190 <ulink url="../user-manual/seealso.html">user-manual</ulink> for
2196 <sect2 renderas="sect3" id="microsuck">
2197 <title>I've noticed that Privoxy changes <quote>Microsoft</quote> to
2198 <quote>MicroSuck</quote>! Why are you manipulating my browsing?</title>
2201 We're not. The text substitutions that you are seeing are disabled
2202 in the default configuration as shipped. You have either manually
2203 activated the <quote><literal>fun</literal></quote> filter which
2204 is clearly labeled <quote>Text replacements for subversive browsing
2205 fun!</quote> or you are using an older Privoxy version and have implicitly
2206 activated it by choosing the <quote>Advanced</quote> profile in the
2207 web-based editor. Please upgrade.
2211 <sect2 renderas="sect3" id="valid">
2212 <title>Does Privoxy produce <quote>valid</quote> HTML (or XHTML)?</title>
2215 Privoxy generates HTML in both its own <quote>templates</quote>, and possibly
2216 whenever there are text substitutions via a &my-app; filter. While this
2217 should always conform to the HTML 4.01 specifications, it has not been
2218 validated against this or any other standard.
2222 <sect2 renderas="sect3" id="surprise-privoxy">
2223 <title>How did you manage to get Privoxy on my computer without my consent?</title>
2226 We didn't. We make Privoxy available for download, but we don't go
2227 around installing it on other people's systems behind their back.
2228 If you discover Privoxy running on your system and are sure you didn't
2229 install it yourself, somebody else did. You may not even be running
2230 the real Privoxy, but maybe something else that only pretends to be
2231 Privoxy, or maybe something that is based on the real Privoxy,
2232 but has been modified.
2235 Lately there have been reports of problems with some kind of
2236 Privoxy versions that come preinstalled on some Netbooks.
2237 Some of the problems described are inconsistent with the behaviour
2238 of official Privoxy versions, which suggests that the preinstalled
2239 software may contain vendor modifications that we don't know about
2240 and thus can't debug.
2243 Privoxy's <link linkend="copyright">license</link> allows vendor
2244 modifications, but the vendor has to comply with the license,
2245 which involves informing the user about the changes and to make
2246 the changes available under the same license as Privoxy itself.
2249 If you are having trouble with a modified Privoxy version,
2250 please try to talk to whoever made the modifications before
2251 reporting the problem to us. Please also try to convince
2252 whoever made the modifications to talk to us. If you think
2253 somebody gave you a modified Privoxy version without complying
2254 to the license, please let us know.
2262 <!-- ~~~~~ New section ~~~~~ -->
2264 <sect1 id="trouble">
2265 <title>Troubleshooting</title>
2267 <sect2 renderas="sect3">
2268 <title id="refused">I cannot connect to any websites. Or, I am getting
2269 <quote>connection refused</quote> message with every web page. Why?</title>
2271 There are several possibilities:
2276 <application>Privoxy</application> is not running. Solution: verify
2277 that &my-app; is installed correctly, has not crashed, and is indeed running.
2278 Turn on <application>Privoxy's</application> logging, and look at the logs to see what they say.
2280 <listitem><para>Or your browser is configured for a different port than what
2281 <application>Privoxy</application> is using. Solution: verify that &my-app;
2282 and your browser are set to the same port (<literal>listen-address</literal>).
2284 <listitem><para>Or if using a forwarding rule, you have a configuration problem or a
2285 problem with a host in the forwarding chain. Solution: temporarily alter your
2286 configuration and take the forwarders out of the equation.
2289 Or you have a firewall that is interfering and blocking you. Solution:
2290 try disabling or removing the firewall as a simple test.
2297 <!-- ~~~~~ New section ~~~~~ -->
2298 <sect2 renderas="sect3" id="error503">
2299 <title>Why am I getting a 503 Error (WSAECONNREFUSED) on every page?</title>
2301 More than likely this is a problem with your TCP/IP networking. ZoneAlarm has
2302 been reported to cause this symptom -- even if not running! The solution is
2303 to either fight the ZA configuration, or uninstall ZoneAlarm, and then find
2304 something better behaved in its place. Other personal firewall type products
2305 may cause similar type problems if not configured correctly.
2309 <sect2 renderas="sect3">
2310 <title id="flushit">I just added a new rule, but the steenkin ad is
2311 still getting through. How?</title>
2313 If the ad had been displayed before you added its URL, it will probably be
2314 held in the browser's cache for some time, so it will be displayed without
2315 the need for any request to the server, and <application>Privoxy</application>
2316 will not be involved. Flush the browser's caches, and then try again.
2320 If this doesn't help, you probably have an error in the rule you
2321 applied. Try pasting the full URL of the offending ad into <ulink
2322 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
2323 and see if it really matches your new rule. Blocking ads is like blocking
2324 spam: a lot of tinkering is required to stay ahead of the game. And
2325 remember you need to block the URL of the ad in question, which may be
2326 entirely different from the site URL itself. Most ads are hosted on different
2327 servers than the main site itself. If you right-click on the ad, you should
2328 be able to get all the relevant information you need. Alternately, you can
2329 find the correct URL by looking at <application>Privoxy's</application> logs
2330 (you may need to enable logging in the main config file if its disabled).
2333 Below is a slightly modified real-life log snippet that originates with one
2334 requested URL: <literal>www.example.com</literal> (name of site was changed
2335 for this example, the number of requests is real). You can see in this the
2336 complexity of what goes into making up this one <quote>page</quote>. There
2337 are eight different domains involved here, with thirty two separate URLs
2338 requested in all, making up all manner of images, Shockwave Flash,
2339 JavaScript, CSS stylesheets, scripts, and other related content. Some of this
2340 content is obviously <quote>good</quote> or <quote>bad</quote>, but not all.
2341 Many of the more questionable looking requests, are going to outside domains
2342 that seem to be identifying themselves with suspicious looking names, making
2343 our job a little easier. &my-app; has <quote>crunched</quote> (meaning caught
2344 and BLOCKED) quite a few items in this example, but perhaps missed a few as well.
2349 Request: www.example.com/
2350 Request: www.example.com/favicon.ico
2351 Request: img.example.com/main.css
2352 Request: img.example.com/sr.js
2353 Request: example.betamarker.com/example.html
2354 Request: www.lik-sang.com/Banners/bestsellers/skyscraper.php?likref=BSellers
2355 Request: img.example.com/pb.png
2356 Request: www.google-analytics.com/urchin.js crunch! (Blocked)
2357 Request: www.advertising-department.com/ats/switch.ps.php?26856 crunch! (Blocked)
2358 Request: img.example.com/p.gif
2359 Request: www.popuptraffic.com/assign.php?l=example&mode=behind crunch! (Blocked)
2360 Request: www.popuptraffic.com/scripts/popup.php?hid=5c3cf&tmpl=PBa.tmpl crunch! (Blocked)
2361 Request: www.popuptraffic.com/assign.php?l=example crunch! (Blocked)
2362 Request: www.lik-sang.com/Banners/best_sellers/best_sellers.css
2363 Request: www.adtrak.net/adx.js crunch! (Blocked)
2364 Request: img.example.com/hbg.gif
2365 Request: img.example.com/example.jpg
2366 Request: img.example.com/mt.png
2367 Request: img.example.com/mm.png
2368 Request: img.example.com/mb.png
2369 Request: www.popuptraffic.com/scripts/popup.php?hid=a71b91fa5&tmpl=Ua.tmp crunch! (Blocked)
2370 Request: www.example.com/tracker.js
2371 Request: www.lik-sang.com/Banners/best_sellers/lsi_head.gif
2372 Request: www.adtrak.net/adjs.php?n=020548130&what=zone:61 crunch! (Blocked)
2373 Request: www.adtrak.net/adjs.php?n=463594413&what=zone:58&source=Ua crunch! (Blocked)
2374 Request: www.lik-sang.com/Banners/best_sellers/bottomani.swf
2375 Request: mmm.elitemediagroup.net/install.php?allowpop=no&popupmincook=0&allowsp2=1 crunch! (Blocked)
2376 Request: www.example.com/tracker.js?screen=1400x1050&win=962x693
2377 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=61 crunch! (Blocked)
2378 Request: 66.70.21.80/scripts/click.php?hid=5c3cf599a9efd0320d26&si
2379 Request: 66.70.21.80/img/pixel.gif
2380 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=58&source=Ua&block=86400 crunch! (Blocked)
2381 Request: 66.70.21.80/scripts/click.php?hid=a71b9f6504b0c5681fa5&si=Ua
2386 Despite 12 out of 32 requests being blocked, the page looked, and seemed to
2387 behave perfectly <quote>normal</quote> (minus some ads, of course).
2392 <sect2 id="badsite" renderas="sect3">
2393 <title >One of my favorite sites does not work with Privoxy.
2394 What can I do?</title>
2397 First verify that it is indeed a <application>Privoxy</application> problem,
2398 by toggling off <application>Privoxy</application> through <ulink
2399 url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>
2400 (the toggle feature may need to be enabled in the main
2401 <filename>config</filename>),
2402 and then shift-reloading the problem page (i.e. holding down the shift key
2403 while clicking reload. Alternatively, flush your browser's disk and memory
2408 If the problem went away, we know we have a configuration related problem.
2410 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
2411 and paste the full URL of the page in question into the prompt. See which
2412 actions are being applied to the URL, and which matches in which actions
2413 files are responsible for that. It might be helpful also to look at your logs
2414 for this site too, to see what else might be happening (note: logging may need
2415 to be enabled in the main config file). Many sites are
2416 complex and require a number of related pages to help present their content.
2417 Look at what else might be used by the page in question, and what of that
2418 might be <emphasis>required</emphasis>.
2419 Now, armed with this information, go to
2421 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
2422 and select the appropriate actions files for editing. </para>
2424 You can now either look for a section which disables the actions that
2425 you suspect to cause the problem and add a pattern for your site there,
2426 or make up a completely new section for your site. In any case, the recommended
2427 way is to disable only the prime suspect, reload the problem page, and only
2428 if the problem persists, disable more and more actions until you have
2429 identified the culprit. You may or may not want to turn the other actions
2430 on again. Remember to flush your browser's caches in between any such changes!
2433 Alternately, if you are comfortable with a text editor, you can accomplish
2434 the same thing by editing the appropriate actions file. Probably the easiest
2435 way to deal with such problems when editing by hand is to add your
2436 site to a <literal>{ fragile }</literal> section in <filename>user.action</filename>,
2437 which is an alias that turns off most <quote>dangerous</quote>
2438 actions, but is also likely to turn off more actions then needed, and thus lower
2439 your privacy and protection more than necessary,
2442 Troubleshooting actions is discussed in more detail in the <ulink
2443 url="../user-manual/appendix.html#ACTIONSANAT">User Manual appendix,
2444 Troubleshooting: the Anatomy of an Action</ulink>.
2445 There is also an <ulink
2446 url="../user-manual/actions-file.html#ACT-EXAMPLES">actions tutorial</ulink>
2447 with general configuration information and examples.
2450 As a last resort, you can always see if your browser has a setting that will
2451 bypass the proxy setting for selective sites. Modern browsers can do this.
2457 <!-- ~~~~~ New section ~~~~~ -->
2458 <sect2 id="dun" renderas="sect3">
2459 <title>After installing Privoxy, I have to log in
2460 every time I start IE. What gives?</title>
2463 This is a quirk that effects the installation of
2464 <application>Privoxy</application>, in conjunction with Internet Explorer and
2465 Internet Connection Sharing on Windows 2000 and Windows XP. The symptoms may
2466 appear to be corrupted or invalid DUN settings, or passwords.
2470 When setting up an NT based Windows system with
2471 <application>Privoxy</application> you may find that things do not seem to be
2472 doing what you expect. When you set your system up you will probably have set
2473 up Internet Connection Sharing (ICS) with Dial up Networking (DUN) when
2474 logged in with administrator privileges. You will probably have made this DUN
2475 connection available to other accounts that you may have set-up on your
2476 system. E.g. Mum or Dad sets up the system and makes accounts suitably
2477 configured for the kids.
2481 When setting up <application>Privoxy</application> in this environment you
2482 will have to alter the proxy set-up of Internet Explorer (IE) for the
2483 specific DUN connection on which you wish to use
2484 <application>Privoxy</application>. When you do this the ICS DUN set-up
2485 becomes user specific. In this instance you will see no difference if you
2486 change the DUN connection under the account used to set-up the connection.
2487 However when you do this from another user you will notice that the DUN
2488 connection changes to make available to "Me only". You will also find that
2489 you have to store the password under each different user!
2493 The reason for this is that each user's set-up for IE is user specific. Each
2494 set-up DUN connection and each LAN connection in IE store the settings for
2495 each user individually. As such this enforces individual configurations
2496 rather than common ones. Hence the first time you use a DUN connection after
2497 re-booting your system it may not perform as you expect, and prompt you for
2498 the password. Just set and save the password again and all should be OK.
2502 [Thanks to Ray Griffith for this submission.]
2507 <!-- ~~~~~ New section ~~~~~ -->
2508 <sect2 id="ftp" renderas="sect3">
2509 <title>I cannot connect to any FTP sites. Privoxy
2510 is blocking me.</title>
2512 <application>Privoxy</application> cannot act as a proxy for FTP traffic,
2513 so do not configure your browser to use <application>Privoxy</application>
2514 as an FTP proxy. The same is true for <emphasis>any protocol other than HTTP
2515 or HTTPS (SSL)</emphasis>.
2518 Most browsers understand FTP as well as HTTP. If you connect to a site, with
2519 a URL like <literal>ftp://ftp.example.com</literal>, your browser is making
2520 an FTP connection, and not a HTTP connection. So while your browser may
2521 speak FTP, <application>Privoxy</application> does not, and cannot proxy
2525 To complicate matters, some systems may have a generic <quote>proxy</quote>
2526 setting, which will enable various protocols, including
2527 <emphasis>both</emphasis> HTTP and FTP proxying! So it is possible to
2528 accidentally enable FTP proxying in these cases. And of course, if this
2529 happens, <application>Privoxy</application> will indeed cause problems since
2530 it does not know FTP. <![%p-newstuff;[Newer version will give a sane error
2531 message if a FTP connection is attempted.]]> Just disable the FTP setting
2532 and all will be well again.
2535 Will <application>Privoxy</application> ever proxy FTP traffic? Unlikely.
2536 There just is not much reason, and the work to make this happen is more than
2541 <!-- ~~~~~ New section ~~~~~ -->
2542 <sect2 id="macosxie" renderas="sect3">
2543 <title>In Mac OS X, I can't configure Microsoft Internet Explorer to use
2544 Privoxy as the HTTP proxy.</title>
2546 Microsoft Internet Explorer (in versions like 5.1) respects system-wide
2547 network settings. In order to change the HTTP proxy, open System
2548 Preferences, and click on the Network icon. In the settings pane that
2549 comes up, click on the Proxies tab. Ensure the "Web Proxy (HTTP)" checkbox
2550 is checked and enter <literal>127.0.0.1</literal> in the entry field.
2551 Enter <literal>8118</literal> in the Port field. The next time you start
2552 IE, it should reflect these values.
2556 <!-- ~~~~~ New section ~~~~~ -->
2557 <sect2 renderas="sect3" id="macosxuninstall">
2558 <title>In Mac OS X, I dragged the Privoxy folder to the trash in order to
2559 uninstall it. Now the finder tells me I don't have sufficient privileges to
2560 empty the trash.</title>
2562 Note: This ONLY applies to privoxy 3.0.6 and earlier.
2565 Just dragging the <application>Privoxy</application> folder to the trash is
2566 not enough to delete it. <application>Privoxy</application> supplies an
2567 <application>uninstall.command</application> file that takes care of
2568 these details. Open the trash, drag the <application>uninstall.command</application>
2569 file out of the trash and double-click on it. You will be prompted for
2570 confirmation and the administration password.
2573 The trash may still appear full after this command; emptying the trash
2574 from the desktop should make it appear empty again.
2578 <!-- ~~~~~ New section ~~~~~ -->
2579 <sect2 renderas="sect3" id="macosximages">
2580 <title>In Mac OS X Panther (10.3), images often fail to load and/or I
2581 experience random delays in page loading. I'm using
2582 <literal>localhost</literal> as my browser's proxy setting.</title>
2584 We believe this is due to an IPv6-related bug in Mac OS X, but don't fully
2585 understand the issue yet. In any case, changing the proxy setting to
2586 <literal>127.0.0.1</literal> instead of <literal>localhost</literal>
2587 works around the problem.
2591 <!-- ~~~~~ New section ~~~~~ -->
2592 <sect2 renderas="sect3" id="macosxaccountdeletion">
2593 <title>I just upgraded to Mac OS X 10.9 (Mavericks) and now &my-app; has stopped
2596 The upgrade process to Mac OS X Mavericks (10.9) from an earlier version of OS
2597 X deletes all user accounts that are either not part of OS X itself or are
2598 not interactive user accounts (ones you log in with). Since, for the sake of
2599 security, &my-app; runs as a non-privileged user that is created by its
2600 installer (_privoxy), it can no longer start up once that account gets deleted.
2601 The solution is to perform a complete uninstall using the supplied
2602 <application>uninstall.command</application> script (either back up your
2603 configuration files or select to not have the uninstaller remove them when it
2604 prompts you) and then reinstall &my-app; using the installer package and merge
2605 in your configuration.
2609 <!-- ~~~~~ New section ~~~~~ -->
2610 <!-- XXX: Is this still relevant now that we have gzip support? -->
2611 <sect2 renderas="sect3" id="blankpage">
2612 <title>I get a completely blank page at one site. <quote>View Source</quote>
2613 shows only: <markup><![CDATA[<html><body></body></html>]]></markup>. Without
2614 Privoxy the page loads fine.</title>
2616 Chances are that the site suffers from a bug in
2617 <ulink url="http://www.php.net/"><application>PHP</application></ulink>,
2618 which results in empty pages being sent if the client explicitly requests
2619 an uncompressed page, like <application>Privoxy</application> does.
2620 This bug has been fixed in PHP 4.2.3.
2623 To find out if this is in fact the source of the problem, try adding
2624 the site to a <literal>-prevent-compression</literal> section in
2625 <filename>user.action</filename>:
2628 # Make exceptions for ill-behaved sites:
2630 {-prevent-compression}
2631 .example.com</screen>
2633 If that works, you may also want to report the problem to the
2634 site's webmasters, telling them to use zlib.output_compression
2635 instead of ob_gzhandler in their PHP applications (workaround)
2636 or upgrade to PHP 4.2.3 or later (fix).
2640 <sect2 renderas="sect3" id="nohostname">
2641 <title>My logs show many <quote>Unable to get my own hostname</quote> lines.
2644 <application>Privoxy</application> tries to get the hostname of the system
2645 its running on from the IP address of the system interface it is bound to
2646 (from the <filename>config</filename> file
2647 <emphasis>listen-address</emphasis> setting). If the system cannot supply
2648 this information, <application>Privoxy</application> logs this condition.
2651 Typically, this would be considered a minor system configuration error. It is
2652 not a fatal error to <application>Privoxy</application> however, but may
2653 result in a much slower response from <application>Privoxy</application> on
2654 some platforms due to DNS timeouts.
2657 This can be caused by a problem with the local <filename>hosts</filename>
2658 file. If this file has been changed from the original, try reverting it to
2659 see if that helps. Make sure whatever name(s) are used for the local system,
2660 that they resolve both ways.
2663 You should also be able to work around the problem with the
2664 <ulink url="../user-manual/config.html#HOSTNAME">hostname option</ulink>.
2668 <sect2 renderas="sect3" id="inuse">
2669 <title>When I try to launch Privoxy, I get an
2670 error message <quote>port 8118 is already in use</quote> (or similar wording).
2673 Port 8118 is <application>Privoxy's</application> default TCP
2674 <quote>listening</quote> port. Typically this message would mean that there
2675 is already one instance of <application>Privoxy</application> running, and
2676 your system is actually trying to start a second
2677 <application>Privoxy</application> on the same port, which will not work.
2678 (You can have multiple instances but they must be assigned different ports.)
2679 How and why this might happen varies from platform to platform, but you need
2680 to check your installation and start-up procedures.
2684 <sect2 renderas="sect3" id="demoronizer">
2686 Pages with UTF-8 fonts are garbled.
2689 This may be the result of an overly aggressive filter. The filters that
2690 are enabled in the default configuration aren't expected to cause problems
2691 like this. If you enabled the <quote>demoronizer</quote> filter, please
2692 try temporarily disabling it.
2695 If that doesn't help, temporarily disable all filters to see if another
2696 filter could be the culprit. If the problem disappears, enable the filters
2697 one by one, until the problem reappears and the offending filter is found.
2700 Once the problem-causing filter is known, it can be fixed or disabled.
2703 Upgrading <application>Privoxy</application>, or going to the most recent
2704 <filename>default.action</filename> file available from <ulink
2705 url="http://sourceforge.net/project/showfiles.php?group_id=11118">SourceForge</ulink>
2706 might be worth a try, too.
2710 <sect2 renderas="sect3" id="demoronizer2">
2712 Why are binary files (such as images) corrupted when Privoxy
2716 This may also be caused by an (<link linkend="DEMORONIZER">overly aggressive
2717 filter</link> in conjunction with a web server that is misreporting the content
2718 type. By default binary files are exempted from
2719 <application>Privoxy's</application> filtering
2720 (unless the web server by mistake says the file is something else).
2724 <sect2 renderas="sect3" id="demoronizer3">
2726 What is the <quote>demoronizer</quote> and why is it there?
2729 The original demoronizer was a Perl script that cleaned up HTML pages which
2730 were created with certain Microsoft products. MS has used proprietary extensions
2731 to standardized font encodings (ISO 8859-1), which has caused problems for pages
2732 that are viewed with non-Microsoft products (and are expecting to see a
2733 standard set of fonts). The demoronizer corrected these errors so the pages
2734 displayed correctly. <application>Privoxy</application> borrowed from this
2735 script, introducing a filter based on the original demoronizer, which in turn could
2736 correct these errors on the fly.
2739 But this is only needed in some situations, and will cause serious problems in some
2743 If you are using Microsoft products, you do not need it. If you need to view
2744 pages with UTF-8 characters (such as Cyrillic or Chinese), then it will
2745 cause corruption of the fonts, and thus <emphasis>should not be on</emphasis>.
2748 On the other hand, if you use non-Microsoft products, and you occasionally
2749 notice weird characters on pages, you might want to try it.
2753 <sect2 renderas="sect3" id="windowopen">
2755 Why do I keep seeing <quote>PrivoxyWindowOpen()</quote> in raw source code?
2758 <application>Privoxy</application> is attempting to disable malicious
2759 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink>
2760 in this case, with the <literal>unsolicited-popups</literal>
2761 filter. <application>Privoxy</application> cannot tell very well
2762 <quote>good</quote> code snippets from <quote>bad</quote> code snippets.
2765 If you see this in HTML source, and the page displays without problems, then
2766 this is good, and likely some pop-up window was disabled. If you see this
2767 where it is causing a problem, such as a downloaded program source code file,
2768 then you should set an exception for this site or page such that the
2769 integrity of the page stays in tact by disabling all filtering.
2773 <sect2 renderas="sect3" id="dnserrors">
2775 I am getting too many DNS errors like <quote>404 No Such Domain</quote>. Why
2776 can't Privoxy do this better?
2779 There are potentially several factors here. First of all, the DNS resolution
2780 is done by the underlying operating system -- not
2781 <application>Privoxy</application> itself. <application>Privoxy</application>
2782 merely initiates the process and hands it off, and then later reports
2783 whatever the outcome was and tries to give a coherent message if there seems
2784 to be a problem. In some cases, this might otherwise be mitigated by the
2785 browser itself which might try some work-arounds and alternate approaches (e.g
2786 adding <quote>www.</quote> to the URL).
2789 In other cases, if <application>Privoxy</application> is being chained
2790 with another proxy, this could complicate the issue, and cause undue
2791 delays and timeouts. In the case of a <quote>socks4a</quote> proxy, the socks
2792 server handles all the DNS. <application>Privoxy</application> would just be
2793 the <quote>messenger</quote> which is reporting whatever problem occurred
2794 downstream, and not the root cause of the error.
2798 In any case, versions newer than 3.0.3 include various improvements to help
2799 <application>Privoxy</application> better handle these cases.
2803 <sect2 renderas="sect3" id="allcpu">
2805 At one site Privoxy just hangs, and starts taking
2806 all CPU. Why is this?
2809 This is probably a manifestation of the <quote>100% cpu</quote> problem that
2810 occurs on pages containing many (thousands upon thousands) of blank lines. The blank lines
2811 are in the raw HTML source of the page, and the browser just ignores them. But the
2812 pattern matching in <application>Privoxy's</application> page filtering
2813 mechanism is trying to match against absurdly long strings and this becomes
2814 very CPU-intensive, taking a long, long time to complete.
2817 Until a better solution comes along, disable filtering on these pages,
2818 particularly the <literal>js-annoyances</literal> and
2819 <literal>unsolicited-popups</literal> filters. If you run into this problem
2820 with a recent &my-app; version, please send a problem report.
2824 <sect2 renderas="sect3" id="slowcrawl">
2825 <title>I just installed Privoxy, and all my
2826 browsing has slowed to a crawl. What gives? </title>
2828 This should not happen, and for the overwhelming number of users world-wide,
2829 it does not happen. I would suspect some inadvertent interaction of software
2830 components such as anti-virus software, spyware protectors, personal
2831 firewalls or similar components. Try disabling (or uninstalling) these one
2832 at a time and see if that helps. Either way, if you are using a
2833 recent &my-app; version, please report the problem.
2837 <sect2 renderas="sect3" id="preventcomp">
2838 <title>Why do my filters work on some sites but not on others? </title>
2840 It's probably due to compression. It is a common practice for web servers to
2841 send their content <quote>compressed</quote> in order to speed things up, and
2842 then let the browser <quote>uncompress</quote> them. When compiled with zlib support
2843 &my-app; can decompress content before filtering, otherwise you may want to enable
2845 url="../user-manual/actions-file.html#PREVENT-COMPRESSION">prevent-compression</ulink>.
2848 As of &my-app; 3.0.9, zlib support is enabled in the default builds.
2853 <sect2 renderas="sect3" id="ssl-warnings">
2854 <title>On some HTTPS sites my browser warns me about unauthenticated content,
2855 the URL bar doesn't get highlighted and the lock symbol appears to be broken.
2856 What's going on?</title>
2858 Probably the browser is requesting ads through HTTPS and &my-app;
2859 is blocking the requests. Privoxy's error messages are delivered
2860 unencrypted and while it's obvious for the browser that the HTTPS
2861 request is already blocked by the proxy, some warn about unauthenticated
2865 To work around the problem you can redirect those requests to an invalid
2866 local address instead of blocking them. While the redirects aren't
2867 encrypted either, many browsers don't care. They simply follow the
2868 redirect, fail to reach a server and display an error message instead
2872 To do that, enable logging to figure out which requests get blocked by
2873 &my-app; and add the hosts (no path patterns) to a section like this:
2878 {+redirect{http://127.0.0.1:0/} -block -limit-connect}
2884 Additionally you have to configure your browser to contact
2885 <quote>127.0.0.1:0</quote> directly (instead of through &my-app;).
2888 To add a proxy exception in <application>Mozilla Firefox</application>
2889 open the <quote>Preferences</quote>, click the <quote>Settings</quote>
2890 button located on the <quote>Network</quote> tab in the <quote>Advanced</quote>
2891 section, and add <quote>127.0.0.1:0</quote> in the <quote>No Proxy for:</quote>
2897 <sect2 renderas="sect3" id="se-linux">
2898 <title>I get selinux error messages. How can I fix this?</title>
2900 Please report the problem to the creator of your selinux policies.
2903 The problem is that some selinux policy writers aren't familiar
2904 with the application they are trying to <quote>secure</quote> and
2905 thus create policies that make no sense.
2908 In <application>Privoxy's</application> case the problem usually
2909 is that the policy only allows outgoing connections for certain
2910 destination ports (e.g. 80 and 443). While this may cover the
2911 standard ports, websites occasionally use other ports as well.
2912 This isn't a security problem and therefore <application>Privoxy's</application>
2913 default configuration doesn't block these requests.
2916 If you really want to block these ports (and don't be able
2917 to load websites that don't use standard ports), you should
2918 configure Privoxy to block these ports as well, so it doesn't
2919 trigger the selinux warnings.
2924 <sect2 renderas="sect3" id="gentoo-ricers">
2925 <title>I compiled &my-app; with Gentoo's portage and it appears to be very slow. Why?</title>
2927 Probably you unintentionally compiled &my-app; without threading support
2928 in which case requests have to be serialized and only one can be served
2932 Check your <quote>USE</quote> flags and make sure they include
2933 <quote>threads</quote>. If they don't, add the flag and rebuild &my-app;.
2936 If you compiled &my-app; with threading support (on POSIX-based systems),
2937 the <quote>Conditional #defines</quote> section on <ulink
2938 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
2939 will list <quote>FEATURE_PTHREAD</quote> as <quote>enabled</quote>.
2946 <!-- ~~~~~ New section ~~~~~ -->
2947 <sect1 id="contact"><title>Contacting the developers, Bug Reporting and Feature Requests</title>
2948 <!-- Include contacting.sgml -->
2950 <!-- end contacting -->
2953 <!-- ~~~~~ New section ~~~~~ -->
2954 <sect1 id="copyright"><title>Privoxy Copyright, License and History</title>
2956 <!-- Include copyright.sgml -->
2962 Portions of this document are <quote>borrowed</quote> from the original
2963 <application>Junkbuster</application> (tm) FAQ, and modified as
2964 appropriate for <application>Privoxy</application>.
2967 <!-- ~~~~~ New section ~~~~~ -->
2968 <sect2><title>License</title>
2969 <!-- Include copyright.sgml: -->
2971 <!-- end copyright -->
2973 <!-- ~ End section ~ -->
2975 <!-- ~~~~~ New section ~~~~~ -->
2976 <sect2><title>History</title>
2977 <!-- Include history.sgml -->
2983 <!-- ~ End section ~ -->
2986 <!-- ~~~~~ New section ~~~~~ -->
2988 <sect1 id="seealso"><title>See also</title>
2990 <!-- Include seealso.sgml -->
3000 This program is free software; you can redistribute it
3001 and/or modify it under the terms of the GNU General
3002 Public License as published by the Free Software
3003 Foundation; either version 2 of the License, or (at
3004 your option) any later version.
3006 This program is distributed in the hope that it will
3007 be useful, but WITHOUT ANY WARRANTY; without even the
3008 implied warranty of MERCHANTABILITY or FITNESS FOR A
3009 PARTICULAR PURPOSE. See the GNU General Public
3010 License for more details.
3012 The GNU General Public License should be included with
3013 this file. If not, you can view it at
3014 http://www.gnu.org/copyleft/gpl.html
3015 or write to the Free Software Foundation, Inc.,
3016 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA