1 Privoxy Frequently Asked Questions
3 Copyright © 2001-2006 by Privoxy Developers
5 $Id: faq.sgml,v 2.23 2006/10/21 22:19:52 hal9 Exp $
7 This FAQ gives quick answers to frequently asked questions about Privoxy. It is
8 not a substitute for the Privoxy User Manual.
12 Privoxy is a web proxy with advanced filtering capabilities for protecting
13 privacy, modifying web page data, managing cookies, controlling access, and
14 removing ads, banners, pop-ups and other obnoxious Internet junk. Privoxy has a
15 very flexible configuration and can be customized to suit individual needs and
16 tastes. Privoxy has application for both stand-alone systems and multi-user
19 Privoxy is based on Internet Junkbuster (tm).
21 Please note that this document is a work in progress. This copy represents the
22 state at the release of version 3.0.6. You can find the latest version of the
23 document at http://www.privoxy.org/faq/. Please see the Contact section if you
24 want to contact the developers.
26 -------------------------------------------------------------------------------
29 1. General Information
31 1.1. Who should use Privoxy?
32 1.2. Is Privoxy the best choice for me?
33 1.3. What is a "proxy"? How does Privoxy work?
34 1.4. Does Privoxy do anything more than ad blocking?
35 1.5. What is this new version of "Junkbuster"?
36 1.6. Why "Privoxy"? Why change the name from Junkbuster at all?
37 1.7. How does Privoxy differ from the old Junkbuster?
38 1.8. How does Privoxy know what is an ad, and what is not?
39 1.9. Can Privoxy make mistakes? This does not sound very scientific.
40 1.10. Will I have to configure Privoxy before I can use it?
41 1.11. Can Privoxy run as a server on a network?
42 1.12. My browser does the same things as Privoxy. Why should I use Privoxy
44 1.13. Why should I trust Privoxy?
45 1.14. Is there is a license or fee? What about a warranty? Registration?
46 1.15. Can Privoxy remove spyware? Adware? Viruses?
47 1.16. Can I use Privoxy with other ad-blocking software?
48 1.17. I would like to help you, what can I do?
50 1.17.1. Would you like to participate?
56 2.1. Which browsers are supported by Privoxy?
57 2.2. Which operating systems are supported?
58 2.3. Can I use Privoxy with my email client?
59 2.4. Can I install Privoxy over Junkbuster?
60 2.5. I just installed Privoxy. Is there anything special I have to do now?
61 2.6. What is the proxy address of Privoxy?
62 2.7. I just installed Privoxy, and nothing is happening. All the ads are
64 2.8. I get a "Privoxy is not being used" dummy page although Privoxy is
65 running and being used.
69 3.1. What exactly is an "actions" file?
70 3.2. The "actions" concept confuses me. Please list some of these
72 3.3. How are actions files configured? What is the easiest way to do this?
73 3.4. There are several different "actions" files. What are the differences?
74 3.5. Where can I get updated Actions Files?
75 3.6. Can I use my old config files?
76 3.7. Why is the configuration so complicated?
77 3.8. How can I make my Yahoo/Hotmail/Gmail account work?
78 3.9. What's the difference between the "Cautious", "Medium" and "Advanced"
80 3.10. Why can I change the configuration with a browser? Does that not
81 raise security issues?
82 3.11. What is the default.filter file? What is a "filter"?
83 3.12. How can I set up Privoxy to act as a proxy for my LAN?
84 3.13. Instead of ads, now I get a checkerboard pattern. I don't want to see
86 3.14. Why would anybody want to see a checkerboard pattern?
87 3.15. I see some images being replaced by a text instead of the
88 checkerboard image. Why and how do I get rid of this?
89 3.16. Can Privoxy run as a service on Win2K/NT/XP?
90 3.17. How can I make Privoxy work with other proxies like Squid or Tor?
91 3.18. Can I just set Privoxy to use port 80 and thus avoid individual
92 browser configuration?
93 3.19. Can Privoxy run as a "transparent" proxy?
94 3.20. How can I configure Privoxy for use with Outlook Express?
95 3.21. How can I have separate rules just for HTML mail?
96 3.22. I sometimes notice cookies sneaking through. How?
97 3.23. Are all cookies bad? Why?
98 3.24. How can I allow permanent cookies for my trusted sites?
99 3.25. Can I have separate configurations for different users?
100 3.26. Can I set-up Privoxy as a whitelist of "good" sites?
101 3.27. How can I turn off ad-blocking?
102 3.28. How can I have custom template pages, like the BLOCKED page?
103 3.29. How can I remove the "Go There Anyway" link from the BLOCKED page?
107 4.1. How much does Privoxy slow my browsing down? This has to add extra
109 4.2. I notice considerable delays in page requests compared to the old
110 Junkbuster. What's wrong?
111 4.3. What are "http://config.privoxy.org/" and "http://p.p/"?
112 4.4. How can I submit new ads, or report problems?
113 4.5. If I do submit missed ads, will they be included in future updates?
114 4.6. Why doesn't anyone answer my support request?
115 4.7. How can I hide my IP address?
116 4.8. Can Privoxy guarantee I am anonymous?
117 4.9. A test site says I am not using a Proxy.
118 4.10. How do I use Privoxy together with Tor?
119 4.11. Might some things break because header information or content is
121 4.12. Can Privoxy act as a "caching" proxy to speed up web browsing?
122 4.13. What about as a firewall? Can Privoxy protect me?
123 4.14. I have large empty spaces / a checkerboard pattern now where ads used
125 4.15. How can Privoxy filter Secure (HTTPS) URLs?
126 4.16. Privoxy runs as a "server". How secure is it? Do I need to take any
128 4.17. How can I temporarily disable Privoxy?
129 4.18. When "disabled" is Privoxy totally out of the picture?
130 4.19. How can I tell Privoxy to totally ignore certain sites?
131 4.20. My logs show Privoxy "crunches" ads, but also its own internal CGI
132 pages. What is a "crunch"?
133 4.21. Can Privoxy effect files that I download from a webserver? FTP
135 4.22. I just downloaded a Perl script, and Privoxy altered it! Yikes, what
137 4.23. Should I continue to use a "HOSTS" file for ad-blocking?
138 4.24. Where can I find more information about Privoxy and related issues?
139 4.25. I've noticed that Privoxy changes "Microsoft" to "MicroSuck"! Why are
140 you manipulating my browsing?
144 5.1. I cannot connect to any websites. Or, I am getting "connection
145 refused" message with every web page. Why?
146 5.2. Why am I getting a 503 Error (WSAECONNREFUSED) on every page?
147 5.3. I just added a new rule, but the steenkin ad is still getting through.
149 5.4. One of my favorite sites does not work with Privoxy. What can I do?
150 5.5. After installing Privoxy, I have to log in every time I start IE. What
152 5.6. I cannot connect to any FTP sites. Privoxy is blocking me.
153 5.7. In Mac OSX, I can't configure Microsoft Internet Explorer to use
154 Privoxy as the HTTP proxy.
155 5.8. In Mac OSX, I dragged the Privoxy folder to the trash in order to
156 uninstall it. Now the finder tells me I don't have sufficient
157 privileges to empty the trash.
158 5.9. In Mac OSX Panther (10.3), images often fail to load and/or I
159 experience random delays in page loading. I'm using localhost as my
160 browser's proxy setting.
161 5.10. I get a completely blank page at one site. "View Source" shows only:
162 <html><body></body></html>. Without Privoxy the page loads fine.
163 5.11. My logs show many "Unable to get my own hostname" lines. Why?
164 5.12. When I try to launch Privoxy, I get an error message "port 8118 is
165 already in use" (or similar wording). Why?
166 5.13. Pages with UTF-8 fonts are garbled.
167 5.14. Why are binary files (such as images) corrupted when Privoxy is used?
168 5.15. What is the "demoronizer" and why is it there?
169 5.16. Why do I keep seeing "PrivoxyWindowOpen()" in raw source code?
170 5.17. I am getting too many DNS errors like "404 No Such Domain". Why can't
171 Privoxy do this better?
172 5.18. At one site Privoxy just hangs, and starts taking all CPU. Why is
174 5.19. I just installed Privoxy, and all my browsing has slowed to a crawl.
176 5.20. Why do my filters work on some sites but not on others?
178 6. Contacting the developers, Bug Reporting and Feature Requests
181 6.2. Reporting Problems
183 6.2.1. Reporting Ads or Other Configuration Problems
184 6.2.2. Reporting Bugs
186 6.3. Request New Features
189 7. Privoxy Copyright, License and History
194 1. General Information
196 1.1. Who should use Privoxy?
198 Anyone that is interested in security, privacy, or in finer-grained control
199 over their web and Internet experience. Everyone is encouraged to try Privoxy.
201 -------------------------------------------------------------------------------
203 1.2. Is Privoxy the best choice for me?
205 Privoxy is certainly a good choice, especially for those who want more control
206 and security. Those that have the ability to fine-tune their installation will
207 benefit the most. One of Privoxy's strength's is that it is highly configurable
208 giving you the ability to completely personalize your installation. Being
209 familiar with, or at least having an interest in learning about HTTP and other
210 networking protocols, HTML, IP (Internet Protocol), and "Regular Expressions"
211 will be a big plus and will help you get the most out of Privoxy. A new
212 installation just includes a very basic configuration. The user should take
213 this as a starting point only, and enhance it as he or she sees fit. In fact,
214 the user is encouraged, and expected to, fine-tune the configuration.
216 Much of Privoxy's configuration can be done with a Web browser. But there are
217 areas where configuration is done using a text editor to edit configuration
220 -------------------------------------------------------------------------------
222 1.3. What is a "proxy"? How does Privoxy work?
224 A web proxy is a service, based on a software such as Privoxy, that clients
225 (i.e. browsers) can use instead of connecting directly to web servers on the
226 Internet. The clients then ask the proxy to fetch the objects they need (web
227 pages, images, movies etc) on their behalf, and when the proxy has done so, it
228 hands the results back to the client. It is a "go-between". See the Wikipedia
229 proxy definition for more.
231 There are many reasons to use web proxies, such as security (firewalling),
232 efficiency (caching) and others, and there are any number of proxies to
233 accommodate those needs.
235 Privoxy is a proxy that is primarily focused on privacy protection, ad and junk
236 elimination and freeing the user from restrictions placed on his activities.
237 Sitting between your browser(s) and the Internet, it is in a perfect position
238 to filter outbound personal information that your browser is leaking, as well
239 as inbound junk. It uses a variety of techniques to do this, all of which are
240 under your complete control via the various configuration files and options.
241 Being a proxy also makes it easier to share configurations among multiple
242 browsers and/or users.
244 -------------------------------------------------------------------------------
246 1.4. Does Privoxy do anything more than ad blocking?
248 Yes, ad blocking is but one possible use. There are many, many ways Privoxy can
249 be used to sanitize and customize web browsing.
251 -------------------------------------------------------------------------------
253 1.5. What is this new version of "Junkbuster"?
255 A long time ago, there was the Internet Junkbuster, by Anonymous Coders and
256 Junkbusters Corporation. This saved many users a lot of pain in the early days
257 of web advertising and user tracking.
259 But the web, its protocols and standards, and with it, the techniques for
260 forcing ads on users, give up autonomy over their browsing, and for tracking
261 them, keeps evolving. Unfortunately, the Internet Junkbuster did not. Version
262 2.0.2, published in 1998, was (and is) the last official release available from
263 Junkbusters Corporation. Fortunately, it had been released under the GNU GPL,
264 which allowed further development by others.
266 So Stefan Waldherr started maintaining an improved version of the software, to
267 which eventually a number of people contributed patches. It could already
268 replace banners with a transparent image, and had a first version of pop-up
269 killing, but it was still very closely based on the original, with all its
270 limitations, such as the lack of HTTP/1.1 support, flexible per-site
271 configuration, or content modification. The last release from this effort was
272 version 2.0.2-10, published in 2000.
274 Then, some developers picked up the thread, and started turning the software
275 inside out, upside down, and then reassembled it, adding many new features
278 The result of this is Privoxy, whose first stable version, 3.0, was released
281 -------------------------------------------------------------------------------
283 1.6. Why "Privoxy"? Why change the name from Junkbuster at all?
285 Though outdated, Junkbusters Corporation continues to offer their original
286 version of the Internet Junkbuster, so publishing our Junkbuster-derived
287 software under the same name led to confusion.
289 There are also potential legal complications from our use of the Junkbuster
290 name, which is a registered trademark of Junkbusters Corporation. There are,
291 however, no objections from Junkbusters Corporation to the Privoxy project
292 itself, and they, in fact, still share our ideals and goals.
294 The developers also believed that there are so many improvements over the
295 original code, that it was time to make a clean break from the past and make a
296 name in their own right.
298 Privoxy is the "Privacy Enhancing Proxy". Also, its content modification and
299 junk suppression gives you, the user, more control, more freedom, and allows
300 you to browse your personal and "private edition" of the web.
302 -------------------------------------------------------------------------------
304 1.7. How does Privoxy differ from the old Junkbuster?
306 Privoxy picks up where Junkbuster left off. All the old features remain. The
307 new Privoxy still blocks ads and banners, still manages cookies, and still
308 helps protect your privacy. But, these are all greatly enhanced, and many, many
309 new features have been added, all in the same vein.
311 The configuration has changed significantly as well. This is something that
312 users will notice right off the bat if upgrading from Junkbuster 2.0.x. The
313 "blocklist" "cookielist", "imagelist" and much more has been combined into the
314 "actions" files, with a completely different syntax. See the What's New page
315 for the latest updates.
317 Privoxy's new features include:
319 * Integrated browser based configuration and control utility at http://
320 config.privoxy.org/ (shortcut: http://p.p/). Browser-based tracing of rule
321 and filter effects. Remote toggling.
323 * Web page filtering (text replacements, removes banners based on size,
324 invisible "web-bugs", JavaScript and HTML annoyances, pop-up windows,
325 header manipulation, etc.)
327 * Modularized configuration that allows for standard settings and user
328 settings to reside in separate files, so that installing updated actions
329 files won't overwrite individual user settings.
331 * HTTP/1.1 compliant (but not all optional 1.1 features are supported).
333 * Support for Perl Compatible Regular Expressions in the configuration files,
334 and generally a more sophisticated and flexible configuration syntax over
337 * Improved cookie management features (e.g. session based cookies).
341 * Bypass many click-tracking scripts (avoids script redirection).
343 * Multi-threaded (POSIX and native threads).
345 * User-customizable HTML templates for all proxy-generated pages (e.g.
348 * Auto-detection and re-reading of config file changes.
350 * Improved signal handling, and a true daemon mode (Unix).
352 * Every feature now controllable on a per-site or per-location basis,
353 configuration more powerful and versatile over-all.
355 * Many smaller new features added, limitations and bugs removed, and security
358 -------------------------------------------------------------------------------
360 1.8. How does Privoxy know what is an ad, and what is not?
362 Privoxy's approach to blocking ads is twofold:
364 First, there are certain patterns in the locations (URLs) of banner images.
365 This applies to both the path (you wouldn't guess how many web sites serve
366 their banners from a directory called "banners"!) and the host (blocking the
367 big banner hosting services like doublecklick.net already helps a lot). Privoxy
368 takes advantage of this fact by using URL patterns to sort out and block the
369 requests for things that sound like they would be ads or banners.
371 Second, banners tend to come in certain sizes. But you can't tell the size of
372 an image by its URL without downloading it, and if you do, it's too late to
373 save bandwidth. Therefore, Privoxy also inspects the HTML sources of web pages
374 while they are loaded, and replaces references to images with standard banner
375 sizes by dummy references, so that your browser doesn't request them anymore in
378 Both of this involves a certain amount of guesswork and is, of course, freely
379 and readily configurable.
381 -------------------------------------------------------------------------------
383 1.9. Can Privoxy make mistakes? This does not sound very scientific.
385 Actually, it's a black art ;-) And yes, it is always possible to have a broad
386 rule accidentally block or change something by mistake. You will almost surely
387 run into such situations at some point. It is tricky writing rules to cover
388 every conceivable possibility, and not occasionally get false positives.
390 But this should not be a big concern since the Privoxy configuration is very
391 flexible, and includes tools to help identify these types of situations so they
392 can be addressed as needed, allowing you to customize your installation. (See
393 the Troubleshooting section below.)
395 -------------------------------------------------------------------------------
397 1.10. Will I have to configure Privoxy before I can use it?
399 No, not really. The default installation should give you a good starting point,
400 and block most ads and unwanted content. Many of the more advanced features are
401 off by default, and would require you to activate them.
403 You do have to set up your browser to use Privoxy (see the Installation section
406 And you will certainly run into situations where there are false positives, or
407 ads not being blocked that you may not want to see. In these cases, you would
408 certainly benefit by customizing Privoxy's configuration to more closely match
409 your individual situation. And we would encourage you to do this. This is where
410 the real power of Privoxy lies!
412 -------------------------------------------------------------------------------
414 1.11. Can Privoxy run as a server on a network?
416 Yes, Privoxy runs as a server already, and can easily be configured to "serve"
417 more than one client. See How can I set up Privoxy to act as a proxy for my LAN
420 -------------------------------------------------------------------------------
422 1.12. My browser does the same things as Privoxy. Why should I use Privoxy at
425 Modern browsers do indeed have some of the same functionality as Privoxy. Maybe
426 this is adequate for you. But Privoxy is much more versatile and powerful, and
427 can do a number of things that browsers just can't.
429 In addition, a proxy is good choice if you use multiple browsers, or have a LAN
430 with multiple computers since Privoxy can run as a server application. This way
431 all the configuration is in one place, and you don't have to maintain a similar
432 configuration for possibly many browsers or users.
434 -------------------------------------------------------------------------------
436 1.13. Why should I trust Privoxy?
438 The most important reason is because you have access to everything, and you can
439 control everything. You can check every line of every configuration file
440 yourself. You can check every last bit of source code should you desire. And
441 even if you can't read code, there should be some comfort in knowing that
442 thousands of other people can, and do read it. You can build the software from
443 scratch, if you want, so that you know the executable is clean, and that it is
444 yours. In fact, we encourage this level of scrutiny. It is one reason we use
447 -------------------------------------------------------------------------------
449 1.14. Is there is a license or fee? What about a warranty? Registration?
451 Privoxy is licensed under the GNU General Public License (GPL). It is free to
452 use, copy, modify or distribute as you wish under the terms of this license.
453 Please see the Copyright section for more information on the license and
454 copyright. Or the LICENSE file that should be included.
456 There is no warranty of any kind, expressed, implied or otherwise. That is
457 something that would cost real money ;-) There is no registration either.
458 Privoxy really is free in every respect!
460 -------------------------------------------------------------------------------
462 1.15. Can Privoxy remove spyware? Adware? Viruses?
464 No. Privoxy cannot remove anything. It is not a removal tool. It is a
465 preventative. Privoxy can help prevent contact from sites that use such tactics
466 with appropriate configuration rules, and thus could conceivably prevent
467 contamination from such sites.
469 -------------------------------------------------------------------------------
471 1.16. Can I use Privoxy with other ad-blocking software?
473 Privoxy should work fine with other proxies and other software in general.
475 But it is probably not necessary to use Privoxy in conjunction with other
476 ad-blocking products, and this could conceivably cause undesirable results. It
477 would be better to choose one software or the other and work a little to tweak
478 its configuration to your liking.
480 -------------------------------------------------------------------------------
482 1.17. I would like to help you, what can I do?
484 1.17.1. Would you like to participate?
486 Well, we always need help. There is something for everybody who wants to help
487 us. We welcome new developers, packagers, testers, documentation writers or
488 really anyone with a desire to help in any way. You DO NOT need to be a
489 "programmer". There are many other tasks available. In fact, the programmers
490 often can't spend as much time programming because of some of the other, more
491 mundane things that need to be done, like checking the Tracker feedback
494 So first thing, get an account on SourceForge.net and mail your id to the
495 developers mailing list. Then, please read the Developer's Manual, at least the
498 -------------------------------------------------------------------------------
502 We, of course, welcome donations and could use money for domain registering,
503 buying software to test Privoxy with, and, of course, for regular world-wide
504 get-togethers (hahaha). If you enjoy the software and feel like helping us with
505 a donation, just drop us a note.
507 -------------------------------------------------------------------------------
511 If you are a vendor of a web-related software like a browser, web server or
512 proxy, and would like us to ensure that Privoxy runs smoothly with your
513 product, you might consider supplying us with a copy or license. We can't,
514 however, guarantee that we will fix all potential compatibility issues as a
517 -------------------------------------------------------------------------------
521 2.1. Which browsers are supported by Privoxy?
523 Any browser that can be configured to use a proxy, which should be virtually
524 all browsers, including Firefox, Internet Explorer, and Opera among others.
525 Direct browser support is not an absolute requirement since Privoxy runs as a
526 separate application and talks to the browser in the standardized HTTP
527 protocol, just like a web server does.
529 -------------------------------------------------------------------------------
531 2.2. Which operating systems are supported?
533 At present, Privoxy is known to run on Windows(95, 98, ME, 2000, XP), Linux
534 (RedHat, SuSE, Debian, Fedora, Gentoo, Slackware and others), Mac OSX, OS/2,
535 AmigaOS, FreeBSD, NetBSD, OpenBSD, Solaris, and various other flavors of Unix.
537 But any operating system that runs TCP/IP, can conceivably take advantage of
538 Privoxy in a networked situation where Privoxy would run as a server on a LAN
539 gateway. Then only the "gateway" needs to be running one of the above operating
542 Source code is freely available, so porting to other operating systems is
543 always a possibility.
545 -------------------------------------------------------------------------------
547 2.3. Can I use Privoxy with my email client?
549 As long as there is some way to set a HTTP proxy for the client, then yes, any
550 application can be used, whether it is strictly speaking a "browser" or not.
551 Though this may not be the best approach for dealing with some of the common
552 abuses of HTML in email. See How can I configure Privoxy with Outlook Express?
553 below for more on this.
555 Be aware that HTML email presents a number of unique security and privacy
556 related issues, that can require advanced skills to overcome. The developers
557 recommend using email clients that can be configured to convert HTML to plain
558 text for these reasons.
560 -------------------------------------------------------------------------------
562 2.4. Can I install Privoxy over Junkbuster?
564 We recommend you un-install Junkbuster first to minimize conflicts and
565 confusion. You may want to save your old configuration files for future
566 reference. The configuration files and syntax have substantially changed, so
567 you will need to manually port your old patterns. See the note to upgraders and
568 installation chapter in the User Manual for details.
570 Note: Some installers may automatically un-install Junkbuster, if present!
572 -------------------------------------------------------------------------------
574 2.5. I just installed Privoxy. Is there anything special I have to do now?
576 All browsers must be told to use Privoxy as a proxy by specifying the correct
577 proxy address and port number in the appropriate configuration area for the
578 browser. See the User Manual for more details. You should also flush your
579 browser's memory and disk cache to get rid of any cached junk items, and remove
582 -------------------------------------------------------------------------------
584 2.6. What is the proxy address of Privoxy?
586 If you set up the Privoxy to run on the computer you browse from (rather than
587 your ISP's server or some networked computer on a LAN), the proxy will be on
588 127.0.0.1 (sometimes referred to as "localhost", which is the special name used
589 by every computer on the Internet to refer to itself) and the port will be 8118
590 (unless you have Privoxy to run on a different port with the listen-address
593 When configuring your browser's proxy settings you typically enter the word
594 "localhost" or the IP address "127.0.0.1" in the boxes next to "HTTP" and
595 "Secure" (HTTPS) and then the number "8118" for "port". This tells your browser
596 to send all web requests to Privoxy instead of directly to the Internet.
598 Privoxy can also be used to proxy for a Local Area Network. In this case, your
599 would enter either the IP address of the LAN host where Privoxy is running, or
600 the equivalent hostname, e.g. 192.168.1.1. Port assignment would be same as
601 above. Note that Privoxy doesn't listen on any LAN interfaces by default.
603 Privoxy does not currently handle any other protocols such as FTP, SMTP, IM,
604 IRC, ICQ, etc. Be sure that proxying any of these other protocols is not
607 -------------------------------------------------------------------------------
609 2.7. I just installed Privoxy, and nothing is happening. All the ads are there.
612 Did you configure your browser to use Privoxy as a proxy? It does not sound
613 like it. See above. You might also try flushing the browser's caches to force a
614 full re-reading of pages. You can verify that Privoxy is running, and your
615 browser is correctly configured by entering the special URL: http://p.p/. This
616 should take you to a page titled "This is Privoxy.." with access to Privoxy's
617 internal configuration. If you see this, then you are good to go. If you
618 receive a page saying "Privoxy is not running", then the browser is not set up
619 to use your Privoxy installation. If you receive anything else (probably
620 nothing at all), it could either be that the browser is not set up correctly,
621 or that Privoxy is not running at all. Check the log file. For instructions on
622 starting Privoxy and browser configuration, see the chapter on starting Privoxy
625 -------------------------------------------------------------------------------
627 2.8. I get a "Privoxy is not being used" dummy page although Privoxy is running
630 First, make sure that Privoxy is really running and being used by visiting
631 http://p.p/. You should see the Privoxy main page. If not, see the chapter on
632 starting Privoxy in the User Manual.
634 Now if http://p.p/ works for you, but other parts of Privoxy's web interface
635 show the dummy page, your browser has cached a redirection it encountered
636 before Privoxy was being used. You need to clear your browser's cache. Note
637 that shift-reloading the dummy page won't help, since that'll only refresh the
638 dummy page, not the redirection that lead you there.
640 The procedure for clearing the cache varies from browser to browser. For
641 example, Mozilla/Netscape users would click Edit --> Preferences --> Advanced
642 --> Cache and then click both "Clear Memory Cache" and "Clear Disk Cache". And,
643 Firefox users would click Tools --> Options --> Privacy --> Cache and then
644 click "Clear Cache Now".
646 -------------------------------------------------------------------------------
650 3.1. What exactly is an "actions" file?
652 Privoxy utilizes the concept of " actions" that are used to manipulate and
653 control web page data. Actions files are where these actions that Privoxy could
654 take while processing a certain request, are configured. Typically, you would
655 define a set of default actions that apply globally to all URLs, then add
656 exceptions to these defaults where needed. There is a wide array of actions
657 available that give the user a high degree of control and flexibility on how to
658 process each and every web page.
660 Actions can be defined on a URL pattern basis, i.e. for single URLs, whole web
661 sites, groups or parts thereof etc. Actions can also be grouped together and
662 then applied to requests matching one or more patterns. There are many possible
663 actions that might apply to any given site. As an example, if you are blocking
664 cookies as one of your default actions, but need to accept cookies from a given
665 site, you would need to define an exception for this site in one of your
666 actions files, preferably in user.action.
668 -------------------------------------------------------------------------------
670 3.2. The "actions" concept confuses me. Please list some of these "actions".
672 For a comprehensive discussion of the actions concept, please refer to the
673 actions file chapter in the User Manual. It includes a list of all actions and
674 an actions file tutorial to get you started.
676 -------------------------------------------------------------------------------
678 3.3. How are actions files configured? What is the easiest way to do this?
680 Actions files are just text files in a special syntax and can be edited with a
681 text editor. But probably the easiest way is to access Privoxy's user interface
682 with your web browser at http://config.privoxy.org/ (Shortcut: http://p.p/) and
683 then select "View & change the current configuration" from the menu.
685 -------------------------------------------------------------------------------
687 3.4. There are several different "actions" files. What are the differences?
689 Three actions files are being included by the developers, to be used for
690 different purposes: These are default.action, the "main" actions file which is
691 actively maintained by the Privoxy developers and typically sets the default
692 policies, user.action, where users are encouraged to make their private
693 customizations, and standard.action, which is for internal Privoxy use only.
694 Please see the actions chapter in the User Manual for a more detailed
697 Earlier versions included three different versions of the default.action file.
698 The new scheme allows for greater flexibility of local configuration, and for
699 browser based selection of pre-defined "aggressiveness" levels.
701 -------------------------------------------------------------------------------
703 3.5. Where can I get updated Actions Files?
705 Based on your feedback and the continuing development, updates of
706 default.action will be made available from time to time on the files section of
709 If you wish to receive an email notification whenever we release updates of
710 Privoxy or the actions file, subscribe to our announce mailing list,
711 ijbswa-announce@lists.sourceforge.net.
713 -------------------------------------------------------------------------------
715 3.6. Can I use my old config files?
717 The syntax and purpose of configuration files has remained the same throughout
718 the 3.x series. Although each release contains updated, "improved" versions and
719 it is recommended to use the newer configuration files. If upgrading from
720 version prior to 3.0.4 the syntax for fast-redirects has changed. See the
721 What's New section of the User Manual for details.
723 But all configuration files have substantially changed from the Junkbuster
724 days, and early versions of Privoxy 2.x. The old files, like blocklist will not
727 Refer to the What's New page for information on configuration changes that may
728 occur from one release to another.
730 -------------------------------------------------------------------------------
732 3.7. Why is the configuration so complicated?
734 "Complicated" is in the eye of the beholder. Those that are familiar with some
735 of the underlying concepts, such as regular expression syntax, take to it like
736 a fish takes to water. Also, software that tries hard to be "user friendly",
737 often lacks sophistication and flexibility. There is always that trade-off
738 there between power vs. easy-of-use. Furthermore, anyone is welcome to
739 contribute ideas and implementations to enhance Privoxy.
741 -------------------------------------------------------------------------------
743 3.8. How can I make my Yahoo/Hotmail/Gmail account work?
745 The default configuration shouldn't impact the usability of any of these
746 services. It may, however, make all cookies temporary, so that your browser
747 will forget your login credentials in between browser sessions. If you would
748 like not to have to log in manually each time you access those websites, simply
749 turn off all cookie handling for them in the user.action file. An example for
750 yahoo might look like:
752 # Allow all cookies for Yahoo login:
754 { -crunch-incoming-cookies -crunch-outgoing-cookies -session-cookies-only }
757 These kinds of sites are often quite complex and heavy with Javascript and thus
758 "fragile". So if still a problem, we have an alias just for such sticky
761 # Gmail is a _fragile_ site:
767 Be sure to flush your browser's caches whenever making these kinds of changes,
768 just to make sure the changes "take".
770 Make sure the domain, host and path are appropriate as well. Your browser can
771 tell you where you are specifically and you should use that information for
772 your configuration settings. Note that above it is not referenced as gmail.com,
773 which is a valid domain name.
775 -------------------------------------------------------------------------------
777 3.9. What's the difference between the "Cautious", "Medium" and "Advanced"
780 Configuring Privoxy is not entirely trivial. To help you get started, we
781 provide you with three different default action "profiles" in the web based
782 actions file editor at http://config.privoxy.org/show-status. See the User
783 Manual for a list of actions, and how the default profiles are set.
785 Where the defaults are likely to break some sites, exceptions for known popular
786 "problem" sites are included, but in general, the more aggressive your default
787 settings are, the more exceptions you will have to make later. New users are
788 best to start off in "Cautious" setting. This is safest and will have the
789 fewest problems. See the User Manual for a more detailed discussion.
791 It should be noted that the "Advanced" profile (formerly known as the
792 "Adventuresome" profile) is more aggressive, and will make use of some of
793 Privoxy's advanced features. Use at your own risk!
795 -------------------------------------------------------------------------------
797 3.10. Why can I change the configuration with a browser? Does that not raise
800 It may seem strange that regular users can edit the config files with their
801 browsers, although the whole /etc/privoxy hierarchy belongs to the user
802 "privoxy", with only 644 permissions.
804 When you use the browser-based editor, Privoxy itself is writing to the config
805 files. Because Privoxy is running as the user "privoxy", it can update the
808 If you run Privoxy for multiple untrusted users (e.g. in a LAN), you will
809 probably want to turn the web-based editor and remote toggle features off by
810 setting "enable-edit-actions 0" and "enable-remote-toggle 0" in the main
813 Note that in the default configuration, only local users (i.e. those on
814 "localhost") can connect to Privoxy, so this is not (normally) a security
817 -------------------------------------------------------------------------------
819 3.11. What is the default.filter file? What is a "filter"?
821 The default.filter file is where filters as supplied by the developers are
822 defined. Filters are a special subset of actions that can be used to modify or
823 remove, web page content on the fly. Filters apply to anything in the page
824 source (and optionally both client and server headers), including HTML tags,
825 and JavaScript. Regular expressions are used to accomplish this. There are a
826 number of pre-defined filters to deal with common annoyances. The filters are
827 only defined here, to invoke them, you need to use the filter action in one of
828 the actions files. Filtering is automatically disabled for inappropriate MIME
831 If you are familiar with regular expressions, and HTML, you can look at the
832 provided default.filter with a text editor and define your own filters. This is
833 potentially a very powerful feature, but requires some expertise in both
834 regular expressions and HTML/HTTP. You should place any modifications to the
835 default filters, or any new ones you create in a separate file, such as
836 user.filter, so they won't be overwritten during upgrades. The ability to
837 define multiple filter files in config is a new feature as of v. 3.0.5.
839 There is no GUI editor option for this part of the configuration, but you can
840 disable/enable the various pre-defined filters of the included default.filter
841 file with the web-based actions file editor.
843 -------------------------------------------------------------------------------
845 3.12. How can I set up Privoxy to act as a proxy for my LAN?
847 By default, Privoxy only responds to requests from 127.0.0.1 (localhost). To
848 have it act as a server for a network, this needs to be changed in the main
849 configuration file. Look for the listen-address option, which may be commented
850 out with a "#" symbol. Make sure it is uncommented, and assign it the address
851 of the LAN gateway interface, and port number to use. Assuming your LAN address
852 is 192.168.1.1 and you wish to run Privoxy on port 8118, this line should look
855 listen-address 192.168.1.1:8118
857 Save the file, and restart Privoxy. Configure all browsers on the network then
858 to use this address and port number.
860 Alternately, you can have Privoxy listen on all available interfaces:
864 And then use Privoxy's permit-access feature to limit connections. A firewall
865 in this situation is recommended as well.
867 The above steps should be the same for any TCP network, regardless of operating
870 If you run Privoxy on a LAN with untrusted users, we recommend that you
871 double-check the access control and security options!
873 -------------------------------------------------------------------------------
875 3.13. Instead of ads, now I get a checkerboard pattern. I don't want to see
878 The replacement for blocked images can be controlled with the set-image-blocker
879 action. You have the choice of a checkerboard pattern, a transparent 1x1 GIF
880 image (aka "blank"), or a redirect to a custom image of your choice. Note that
881 this choice only has effect for images which are blocked as images, i.e. whose
882 URLs match both a handle-as-image and block action.
884 If you want to see nothing, then change the set-image-blocker action to
885 "blank". This can be done by editing the user.action file, or through the
886 web-based actions file editor.
888 -------------------------------------------------------------------------------
890 3.14. Why would anybody want to see a checkerboard pattern?
892 Remember that telling which image is an ad and which isn't, is an educated
893 guess. While we hope that the standard configuration is rather smart, it will
894 make occasional mistakes. The checkerboard image is visually decent, and it
895 shows you where images have been blocked, which can be very helpful in case
896 some navigation aid or otherwise innocent image was erroneously blocked. It is
897 recommended for new users so they can "see" what is happening. Some people
898 might also enjoy seeing how many banners they don't have to see.
900 -------------------------------------------------------------------------------
902 3.15. I see some images being replaced by a text instead of the checkerboard
903 image. Why and how do I get rid of this?
905 This happens when the banners are not embedded in the HTML code of the page
906 itself, but in separate HTML (sub)documents that are loaded into (i)frames or
907 (i)layers, and these external HTML documents are blocked. Being non-images they
908 get replaced by a substitute HTML page rather than a substitute image, which
909 wouldn't work out technically, since the browser expects and accepts only HTML
910 when it has requested an HTML document.
912 The substitute page adapts to the available space and shows itself as a
913 miniature two-liner if loaded into small frames, or full-blown with a large red
914 "BLOCKED" banner if space allows.
916 If you prefer the banners to be blocked by images, you must see to it that the
917 HTML documents in which they are embedded are not blocked. Clicking the "See
918 why" link offered in the substitute page will show you which rule blocked the
919 page. After changing the rule and un-blocking the HTML documents, the browser
920 will try to load the actual banner images and the usual image blocking will
921 (hopefully!) kick in.
923 -------------------------------------------------------------------------------
925 3.16. Can Privoxy run as a service on Win2K/NT/XP?
927 Yes. Version 3.0.5 introduces full Windows service functionality. See the User
928 Manual for details on how to install and configure Privoxy as a service.
930 Earlier 3.x versions could run as a system service using srvany.exe. See the
931 discussion at http://sourceforge.net/tracker/?func=detail&atid=361118&aid=
932 485617&group_id=11118, for details, and a sample configuration.
934 -------------------------------------------------------------------------------
936 3.17. How can I make Privoxy work with other proxies like Squid or Tor?
938 This can be done and is often useful to combine the benefits of Privoxy with
939 those of a another proxy. See the forwarding chapter in the User Manual which
940 describes how to do this, and the How do I use Privoxy together with Tor
943 -------------------------------------------------------------------------------
945 3.18. Can I just set Privoxy to use port 80 and thus avoid individual browser
948 No, its more complicated than that. This only works with special kinds of
949 proxies known as "transparent" proxies (see below).
951 -------------------------------------------------------------------------------
953 3.19. Can Privoxy run as a "transparent" proxy?
955 No, Privoxy currently does not have this ability, though it may be added in a
956 future release. Transparent proxies require special handling of the request
957 headers beyond what Privoxy is now capable of.
959 Chaining Privoxy behind another proxy that has this ability should work though.
960 See the forwarding chapter in the User Manual. As a transparent proxy to be
961 used for chaining we suggest Transproxy (http://transproxy.sourceforge.net/).
963 -------------------------------------------------------------------------------
965 3.20. How can I configure Privoxy for use with Outlook Express?
967 Outlook Express uses Internet Explorer components to both render HTML, and
968 fetch any HTTP requests that may be embedded in an HTML email. So however you
969 have Privoxy configured to work with IE, this configuration should
970 automatically be shared.
972 -------------------------------------------------------------------------------
974 3.21. How can I have separate rules just for HTML mail?
976 The short answer is, you can't. Privoxy has no way of knowing which particular
977 application makes a request, so there is no way to distinguish between web
978 pages and HTML mail. Privoxy just blindly proxies all requests. In the case of
979 Outlook Express (see above), OE uses IE anyway, and there is no way for Privoxy
980 to ever be able to distinguish between them (nor could any other proxy type
981 application for that matter).
983 For a good discussion of some of the issues involved (including privacy and
984 security issues), see http://sourceforge.net/tracker/?func=detail&atid=211118&
985 aid=629518&group_id=11118.
987 -------------------------------------------------------------------------------
989 3.22. I sometimes notice cookies sneaking through. How?
991 Cookies can be set in several ways. The classic method is via the Set-Cookie
992 HTTP header. This is straightforward, and an easy one to manipulate, such as
993 the Privoxy concept of session-cookies-only. There is also the possibility of
994 using Javascript to set cookies (Privoxy calls these content-cookies). This is
995 trickier because the syntax can vary widely, and thus requires a certain amount
996 of guesswork. It is not realistic to catch all of these short of disabling
997 Javascript, which would break many sites. And lastly, if the cookies are
998 embedded in a HTTPS/SSL secure session via Javascript, they are beyond
1001 All in all, Privoxy can help manage cookies in general, can help minimize the
1002 loss of privacy posed by cookies, but can't realistically stop all cookies.
1004 -------------------------------------------------------------------------------
1006 3.23. Are all cookies bad? Why?
1008 No, in fact there are many beneficial uses of cookies. Cookies are just a
1009 method that browsers can use to store data between pages, or between browser
1010 sessions. Sometimes there is a good reason for this, and the user's life is a
1011 bit easier as a result. But there is a long history of some websites taking
1012 advantage of this layer of trust, and using the data they glean from you and
1013 your browsing habits for their own purposes, and maybe to your potential
1014 detriment. Such sites are using you and storing their data on your system. That
1015 is why the security conscious watch from whom those cookies come, and why they
1016 really need to be there.
1018 See the Wikipedia cookie definition for more.
1020 -------------------------------------------------------------------------------
1022 3.24. How can I allow permanent cookies for my trusted sites?
1024 There are several actions that relate to cookies. The default behavior is to
1025 allow only "session cookies", which means the cookies only last for the current
1026 browser session. This eliminates most kinds of abuse related to cookies. But
1027 there may be cases where we want cookies to last.
1029 To disable all cookie actions, so that cookies are allowed unrestricted, both
1030 in and out, for example.com:
1032 { -crunch-incoming-cookies -crunch-outgoing-cookies -session-cookies-only -filter{content-cookies} }
1035 Place the above in user.action. Note some of these may be off by default
1036 anyway, so this might be redundant, but there is no harm being explicit in what
1037 you want to happen. user.action includes an alias for this situation, called
1040 -------------------------------------------------------------------------------
1042 3.25. Can I have separate configurations for different users?
1044 Each instance of Privoxy has its own configuration, including such attributes
1045 as the TCP port that it listens on. What you can do is run multiple instances
1046 of Privoxy, each with a unique listen-address configuration setting, and
1047 configuration path, and then each of these can have their own configurations.
1048 Think of it as per-port configuration.
1050 Simple enough for a few users, but for large installations, consider having
1051 groups of users that might share like configurations.
1053 -------------------------------------------------------------------------------
1055 3.26. Can I set-up Privoxy as a whitelist of "good" sites?
1057 Sure. There are a couple of things you can do for simple white-listing. Here's
1060 ############################################################
1062 ############################################################
1064 / # Block *all* URLs
1066 ############################################################
1068 ############################################################
1074 This allows access to only those three sites by first blocking all URLs, and
1075 then subsequently allowing three specific exceptions.
1077 A more interesting approach is Privoxy's trustfile concept, which incorporates
1078 the notion of "trusted referrers". See the User Manual Trust documentation.
1080 These are fairly simple approaches and are not completely foolproof. There are
1081 various other configuration options that should be disabled (described
1082 elsewhere here and in the User Manual) so that users can't modify their own
1083 configuration and easily circumvent the whitelist.
1085 -------------------------------------------------------------------------------
1087 3.27. How can I turn off ad-blocking?
1089 Ad blocking is achieved through a complex application of various Privoxy
1090 actions. These actions are deployed against simple images, banners, flash
1091 animations, text pages, JavaScript, pop-ups and pop-unders, etc., so its not as
1092 simple as just turning one or two actions off. The various actions that make up
1093 Privoxy ad blocking are hard-coded into the default configuration files. It has
1094 been assumed that everyone using Privoxy is interested in this particular
1097 If you want to do without this, there are several approaches you can take: You
1098 can manually undo the many block rules in default.action. Or even easier, just
1099 create your own default.action file from scratch without the many ad blocking
1100 rules, and corresponding exceptions. Or lastly, if you are not concerned about
1101 the additional blocks that are done for privacy reasons, you can very easily
1102 over-ride all blocking with the following very simple rule in your user.action:
1104 # Unblock everybody, everywhere
1106 / # UN-Block *all* URLs
1108 Or even a more comprehensive reversing of various ad related actions:
1110 # Unblock everybody, everywhere, and turn off appropriate filtering, etc
1112 -filter{banners-by-size} \
1113 -filter{banners-by-link} \
1116 / # UN-Block *all* URLs and allow ads
1118 This last "action" in this compound statement, allow-popups, is an alias that
1119 disables various pop-up blocking features.
1121 -------------------------------------------------------------------------------
1123 3.28. How can I have custom template pages, like the BLOCKED page?
1125 Privoxy "templates" are specialized text files utilized by Privoxy for various
1126 purposes and can easily be modified using any text editor. All the template
1127 pages are installed in a sub-directory appropriately named: templates. Knowing
1128 something about HTML syntax will of course be helpful. You cannot rename any of
1129 these files, or create completely new templates, that is not possible. But you
1130 can change the page content to whatever you like. Be forewarned that these
1131 files are subject to being overwritten during upgrades, so be sure to save any
1134 -------------------------------------------------------------------------------
1136 3.29. How can I remove the "Go There Anyway" link from the BLOCKED page?
1138 Editing the BLOCKED template page (see above) may dissuade some users, but this
1139 method is easily circumvented. Where you need this level of control, you should
1140 build Privoxy from source, and enable various features that are available as
1141 compile-time options. You should configure the sources as follows:
1143 ./configure --disable-toggle --disable-editor --disable-force
1145 This will create an executable with hard-coded security features so that
1146 Privoxy does not allow easy bypassing of blocked sites, or changing the current
1147 configuration via any connected user's web browser. Some of these features can
1148 also be toggled on/off via options in Privoxy's main config file. But
1149 compiled-in compliance is a much better method of ensuring that a block is
1152 Default builds of Privoxy are typically built with these features disabled.
1154 -------------------------------------------------------------------------------
1158 4.1. How much does Privoxy slow my browsing down? This has to add extra time to
1161 How much of an impact depends on many things, including the CPU of the host
1162 system, how aggressive the configuration is, which specific actions are being
1163 triggered, the size of the page, the bandwidth of the connection, etc.
1165 Overall, it should not slow you down any in real terms, and may actually help
1166 speed things up since ads, banners and other junk are not typically being
1167 retrieved and displayed. The actual processing time required by Privoxy itself
1168 for each page, is relatively small in the overall scheme of things, and happens
1169 very quickly. This is typically more than offset by time saved not downloading
1170 and rendering ad images (if ad blocking is being used).
1172 "Filtering" content via the filter or deanimate-gifs actions will certainly
1173 cause a perceived slowdown, since the entire document needs to be buffered
1174 before displaying. And on very large documents, filtering may have some
1175 measurable impact. How much depends on the page size, the actual definition of
1176 the filter(s), etc. See below. Most other actions have little to no impact on
1179 Also, when filtering is enabled, typically there is a disabling of compression,
1180 (see prevent-compression). This can have an impact on speed as well. Again, the
1181 page size, etc. will determine how much of an impact.
1183 -------------------------------------------------------------------------------
1185 4.2. I notice considerable delays in page requests compared to the old
1186 Junkbuster. What's wrong?
1188 If you use any filter action, such as filtering banners by size, web-bugs etc,
1189 or the deanimate-gifs action, the entire document must be loaded into memory in
1190 order for the filtering mechanism to work, and nothing is sent to the browser
1193 The loading time typically does not really change much in real numbers, but the
1194 feeling is different, because most browsers are able to start rendering
1195 incomplete content, giving the user a feeling of "it works". This effect is
1196 more noticeable on slower dialup connections. Extremely large documents may
1197 have some impact on the time to load the page where there is filtering being
1198 done. But overall, the difference should be very minimal. If there is a big
1199 impact, then probably some other situation is contributing (like anti-virus
1202 Filtering is automatically disabled for inappropriate MIME types. But note that
1203 if the web server mis-reports the MIME type, then content that should not be
1204 filtered, could be. Privoxy only knows how to differentiate filterable content
1205 because of the MIME type as reported by the server, or because of some
1206 configuration setting that enables/disables filtering.
1208 -------------------------------------------------------------------------------
1210 4.3. What are "http://config.privoxy.org/" and "http://p.p/"?
1212 http://config.privoxy.org/ is the address of Privoxy's built-in user interface,
1213 and http://p.p/ is a shortcut for it.
1215 Since Privoxy sits between your web browser and the Internet, it can simply
1216 intercept requests for these addresses and answer them with its built-in "web
1219 This also makes for a good test for your browser configuration: If entering the
1220 URL http://config.privoxy.org/ takes you to a page saying "This is Privoxy
1221 ...", everything is OK. If you get a page saying "Privoxy is not working"
1222 instead, then your browser didn't use Privoxy for the request, hence it could
1223 not be intercepted, and you have accessed the real web site at
1226 With recent versions of Privoxy (version 2.9.x and later), the user interface
1227 features information on the run time status, the configuration, and even a
1228 built-in editor for the actions files.
1230 Note that the built-in URLs from earlier versions of Junkbuster / Privoxy,
1231 http://example.com/show-proxy-args and http://i.j.b/, are no longer supported.
1232 If you still use such an old version, you should really consider upgrading to
1235 -------------------------------------------------------------------------------
1237 4.4. How can I submit new ads, or report problems?
1239 Please see the Contact section for various ways to interact with the
1242 -------------------------------------------------------------------------------
1244 4.5. If I do submit missed ads, will they be included in future updates?
1246 Whether such submissions are eventually included in the default.action
1247 configuration file depends on how significant the issue is. We of course want
1248 to address any potential problem with major, high-profile sites such as Google,
1249 Yahoo, etc. Any site with global or regional reach, has a good chance of being
1250 a candidate. But at the other end of the spectrum are any number of smaller,
1251 low-profile sites such as for local clubs or schools. Since their reach and
1252 impact are much less, they are best handled by inclusion in the user's
1253 user.action, and thus would be unlikely to be included.
1255 -------------------------------------------------------------------------------
1257 4.6. Why doesn't anyone answer my support request?
1259 Rest assured that it has been read and considered. Why it is not answered,
1260 could be for various reasons, including no one has a good answer for it, no one
1261 has had time to yet investigate it thoroughly, it has been reported numerous
1262 times already, or because not enough information was provided to help us help
1263 you. Your efforts are not wasted, and we do appreciate them.
1265 -------------------------------------------------------------------------------
1267 4.7. How can I hide my IP address?
1269 If you run both the browser and Privoxy locally, you cannot hide your IP
1270 address with Privoxy or ultimately any other software alone. The server needs
1271 to know your IP address so that it knows where to send the responses back.
1273 There are many publicly usable "anonymous" proxies out there, which provide a
1274 further level of indirection between you and the web server.
1276 However, these proxies are called "anonymous" because you don't need a
1277 password, not because they would offer any real anonymity. Most of them will
1278 log your IP address and make it available to the authorities in case you
1279 violate the law of the country they run in. In fact you can't even rule out
1280 that some of them only exist to *collect* information on (those suspicious)
1281 people with a more than average preference for privacy.
1283 Your best bet is to chain Privoxy with Tor, an EFF supported onion routing
1284 system. The configuration details can be found in How do I use Privoxy together
1285 with Tor section just below.
1287 -------------------------------------------------------------------------------
1289 4.8. Can Privoxy guarantee I am anonymous?
1291 No. Your chances of remaining anonymous are greatly improved, but unless you
1292 chain Privoxy with Tor or a similar system and know what you're doing when it
1293 comes to configuring the rest of your system, it would be safest to assume that
1294 everything you do on the Web can be traced back to you.
1296 Privoxy can remove various information about you, and allows you more freedom
1297 to decide which sites you can trust, and what details you want to reveal. But
1298 it neither hides your IP address, nor can it guarantee that the rest of the
1299 system behaves correctly. There are several possibilities how a web sites can
1300 find out who you are, even if you are using a strict Privoxy configuration and
1301 chained it with Tor.
1303 Most of Privoxy's protection can be easily subverted by an insecure browser
1304 configuration, therefore you should use a browser that can be configured to
1305 only execute code from trusted sites, and be careful which sites you trust. For
1306 example there is no point in having Privoxy modify the User-Agent header, if
1307 websites can get all the information they want through JavaScript, ActiveX,
1310 A few browsers disclose the user's email address in certain situations, such as
1311 when transferring a file by FTP. Privoxy does not filter FTP. If you need this
1312 feature, or are concerned about the mail handler of your browser disclosing
1313 your email address, you might consider products such as NSClean.
1315 Browsers available only as binaries could use non-standard headers to give out
1316 any information they can have access to: see the manufacturer's license
1317 agreement. It's impossible to anticipate and prevent every breach of privacy
1318 that might occur. The professionally paranoid prefer browsers available as
1319 source code, because anticipating their behavior is easier. Trust the source,
1322 -------------------------------------------------------------------------------
1324 4.9. A test site says I am not using a Proxy.
1326 Good! Actually, they are probably testing for some other kinds of proxies.
1327 Hiding yourself completely would require additional steps.
1329 -------------------------------------------------------------------------------
1331 4.10. How do I use Privoxy together with Tor?
1333 Before you configure Privoxy to use Tor (http://tor.eff.org/), please follow
1334 the User Manual chapters 2. Installation and 5. Startup to make sure Privoxy
1335 itself is setup correctly.
1337 If it is, refer to Tor's extensive documentation to learn how to install Tor,
1338 and make sure Tor's logfile says that "Tor has successfully opened a circuit"
1339 and it "looks like client functionality is working".
1341 If either Tor or Privoxy isn't working, their combination most likely will
1342 neither. Testing them on their own will also help you to direct problem reports
1343 to the right audience. If Privoxy isn't working, don't bother the Tor
1344 developers. If Tor isn't working, don't send bug reports to the Privoxy Team.
1346 If you verified that Privoxy and Tor are working, it is time to connect them.
1347 As far as Privoxy is concerned, Tor is just another proxy that can be reached
1348 by socks4 or socks4a. Most likely you are interested in Tor to increase your
1349 anonymity level, therefore you should use socks4a, to make sure Privoxy's DNS
1350 requests are done through Tor and thus invisible to your local network.
1352 Since Privoxy 3.0.5, its main configuration file is already prepared for Tor,
1353 if you are using a default Tor configuration and run it on the same system as
1354 Privoxy, you just have to edit the forwarding section and uncomment the line:
1356 # forward-socks4a / 127.0.0.1:9050 .
1359 This is enough to reach the Internet, but additionally you should uncomment the
1360 following forward rules, to make sure your local network is still reachable
1363 # forward 192.168.*.*/ .
1364 # forward 10.*.*.*/ .
1365 # forward 127.*.*.*/ .
1368 Unencrypted connections to systems in these address ranges will be as (un)
1369 secure as the local network is, but the alternative is that you can't reach the
1370 network at all. If you also want to be able to reach servers in your local
1371 network by using their names, you will need additional exceptions that look
1374 # forward localhost/ .
1377 Save the modified configuration file and open http://config.privoxy.org/
1378 show-status/ in your browser, confirm that Privoxy has reloaded its
1379 configuration and that there are no other forward lines, unless you know that
1380 you need them. If everything looks good, refer to Tor Faq 4.2 to learn how to
1381 verify that you are really using Tor.
1383 Afterward, please take the time to at least skim through the rest of Tor's
1384 documentation. Make sure you understand what Tor does, why it is no replacement
1385 for application level security, and why you shouldn't use it for unencrypted
1388 -------------------------------------------------------------------------------
1390 4.11. Might some things break because header information or content is being
1393 Definitely. It is common for sites to use browser type, browser version, HTTP
1394 header content, and various other techniques in order to dynamically decide
1395 what to display and how to display it. What you see, and what I see, might be
1396 very different. There are many, many ways that this can be handled, so having
1397 hard and fast rules, is tricky.
1399 "User-Agent" is often used in this way to identify the browser, and adjust
1400 content accordingly. Changing this now (at least not further than removing the
1401 OS information) is not recommended, since so many sites do look for it. You may
1402 get undesirable results by changing just this one aspect.
1404 Also, different browsers use different encodings of Russian and Czech
1405 characters, certain web servers convert pages on-the-fly according to the User
1406 Agent header. Giving a "User Agent" with the wrong operating system or browser
1407 manufacturer causes some sites in these languages to be garbled; Surfers to
1408 Eastern European sites should change it to something closer. And then some page
1409 access counters work by looking at the "Referer" header; they may fail or break
1410 if unavailable. The weather maps of Intellicast have been blocked by their
1411 server when no "Referer" or cookie is provided, is another example. (But you
1412 can forge both headers without giving information away). There are many other
1413 ways things that can go wrong when trying to fool a web server. The results of
1414 which could inadvertently cause pages to load incorrectly, partially, or even
1415 not at all. And there may be no obvious clues as to just what went wrong, or
1416 why. Nowhere will there be a message that says "Turn off fast-redirects or
1419 Similar thoughts apply to modifying JavaScript, and, to a lesser degree, HTML
1422 If you have problems with a site, you will have to adjust your configuration
1423 accordingly. Cookies are probably the most likely adjustment that may be
1424 required, but by no means the only one.
1426 -------------------------------------------------------------------------------
1428 4.12. Can Privoxy act as a "caching" proxy to speed up web browsing?
1430 No, it does not have this ability at all. You want something like Squid for
1431 this. And, yes, before you ask, Privoxy can co-exist with other kinds of
1432 proxies like Squid. See the forwarding chapter in the user manual for details.
1434 -------------------------------------------------------------------------------
1436 4.13. What about as a firewall? Can Privoxy protect me?
1438 Not in the way you mean, or in the way a true firewall can. Privoxy can help
1439 protect your privacy, but not protect you from intrusion attempts. It is, of
1440 course, perfectly possible and recommended to use both.
1442 -------------------------------------------------------------------------------
1444 4.14. I have large empty spaces / a checkerboard pattern now where ads used to
1447 It is technically possible to eliminate banners and ads in a way that frees
1448 their allocated page space. This could easily be done by blocking with
1449 Privoxy's filters, and eliminating the entire image references from the HTML
1452 But, this would consume considerably more CPU resources (IOW, slow things
1453 down), would likely destroy the layout of some web pages which rely on the
1454 banners utilizing a certain amount of page space, and might fail in other
1455 cases, where the screen space is reserved (e.g. by HTML tables for instance).
1456 Also, making ads and banners disappear without any trace complicates
1457 troubleshooting, and would sooner or later be problematic.
1459 The better alternative is to instead let them stay, and block the resulting
1460 requests for the banners themselves as is now the case. This leaves either
1461 empty space, or the familiar checkerboard pattern.
1463 So the developers won't support this in the default configuration, but you can
1464 of course define appropriate filters yourself to achieve this.
1466 -------------------------------------------------------------------------------
1468 4.15. How can Privoxy filter Secure (HTTPS) URLs?
1470 Since secure HTTP connections are encrypted SSL sessions between your browser
1471 and the secure site, and are meant to be reliably secure, there is little that
1472 Privoxy can do but hand the raw gibberish data though from one end to the other
1475 The only exception to this is blocking by host patterns, as the client needs to
1476 tell Privoxy the name of the remote server, so that Privoxy can establish the
1477 connection. If that name matches a host-only pattern, the connection will be
1480 As far as ad blocking is concerned, this is less of a restriction than it may
1481 seem, since ad sources are often identifiable by the host name, and often the
1482 banners to be placed in an encrypted page come unencrypted nonetheless for
1483 efficiency reasons, which exposes them to the full power of Privoxy's ad
1486 "Content cookies" (those that are embedded in the actual HTML or JS page
1487 content, see filter{content-cookies}), in an SSL transaction will be impossible
1488 to block under these conditions. Fortunately, this does not seem to be a very
1489 common scenario since most cookies come by traditional means.
1491 -------------------------------------------------------------------------------
1493 4.16. Privoxy runs as a "server". How secure is it? Do I need to take any
1494 special precautions?
1496 There are no known exploits that might affect Privoxy. On Unix-like systems,
1497 Privoxy can run as a non-privileged user, which is how we recommend it be run.
1498 Also, by default Privoxy only listens to requests from "localhost" only. The
1499 server aspect of Privoxy is not itself directly exposed to the Internet in this
1500 configuration. If you want to have Privoxy serve as a LAN proxy, this will have
1501 to be opened up to allow for LAN requests. In this case, we'd recommend you
1502 specify only the LAN gateway address, e.g. 192.168.1.1, in the main Privoxy
1503 configuration file and check all access control and security options. All LAN
1504 hosts can then use this as their proxy address in the browser proxy
1505 configuration, but Privoxy will not listen on any external interfaces. ACLs can
1506 be defined in addition, and using a firewall is always good too. Better safe
1509 -------------------------------------------------------------------------------
1511 4.17. How can I temporarily disable Privoxy?
1513 The easiest way is to access Privoxy with your browser by using the remote
1514 toggle URL: http://config.privoxy.org/toggle. See the Bookmarklets section of
1515 the User Manual for an easy way to access this feature.
1517 -------------------------------------------------------------------------------
1519 4.18. When "disabled" is Privoxy totally out of the picture?
1521 No, this just means all filtering and actions are disabled. Privoxy is still
1522 acting as a proxy, but just not doing any of the things that Privoxy would
1523 normally be expected to do. It is still a "middle-man" in the interaction
1524 between your browser and web sites. See below to bypass the proxy.
1526 -------------------------------------------------------------------------------
1528 4.19. How can I tell Privoxy to totally ignore certain sites?
1530 Bypassing a proxy, or proxying based on arbitrary criteria, is purely a browser
1531 configuration issue, not a Privoxy issue. Modern browsers typically do have
1532 settings for not proxying certain sites. Check your browser's help files.
1534 -------------------------------------------------------------------------------
1536 4.20. My logs show Privoxy "crunches" ads, but also its own internal CGI pages.
1539 A "crunch" simply means Privoxy intercepted something, nothing more. Often this
1540 is indeed ads or banners, but Privoxy uses the same mechanism for trapping
1541 requests for its own internal pages. For instance, a request for Privoxy's
1542 configuration page at: http://config.privoxy.org, is intercepted (i.e. it does
1543 not go out to the 'net), and the familiar CGI configuration is returned to the
1544 browser, and the log consequently will show a "crunch".
1546 -------------------------------------------------------------------------------
1548 4.21. Can Privoxy effect files that I download from a webserver? FTP server?
1550 From the webserver's perspective, there is no difference between viewing a
1551 document (i.e. a page), and downloading a file. The same is true of Privoxy. If
1552 there is a match for a block pattern, it will still be blocked, and of course
1555 Filtering is potentially more of a concern since the results are not always so
1556 obvious, and the effects of filtering are there whether the file is simply
1557 viewed, or downloaded. And potentially whether the content is some obnoxious
1558 advertisement, or Mr. Jimmy's latest/greatest source code jewel. Of course, one
1559 of these presumably is "bad" content that we don't want, and the other is
1560 "good" content that we do want. Privoxy is blind to the differences, and can
1561 only distinguish "good from bad" by the configuration parameters we give it.
1563 Privoxy knows the differences in files according to the "Document Type" as
1564 reported by the webserver. If this is reported accurately (e.g. "application/
1565 zip" for a zip archive), then Privoxy knows to ignore these where appropriate.
1566 Privoxy potentially can filter HTML as well as plain text documents, subject to
1567 configuration parameters of course. Also, documents that are of an unknown type
1568 (generally assumed to be "text/plain") can be filtered, as will those that
1569 might be incorrectly reported by the webserver. If such a file is a downloaded
1570 file that is intended to be saved to disk, then any content that might have
1571 been altered by filtering, will be saved too, for these (probably rare) cases.
1573 Note that versions later than 3.0.2 do NOT filter document types reported as
1574 "text/plain". Prior to this, Privoxy did filter this document type.
1576 In short, filtering is "ON" if a) the Document Type as reported by the
1577 webserver is appropriate and b) the configuration allows it (or at least does
1578 not disallow it). That's it. There is no magic cookie anywhere to say this is
1579 "good" and this is "bad". It's the configuration that let's it all happen or
1582 If you download text files, you probably do not want these to be filtered,
1583 particularly if the content is source code, or other critical content. Source
1584 code sometimes might be mistaken for Javascript (i.e. the kind that might open
1585 a pop-up window). It is recommended to turn off filtering for download sites
1586 (particularly if the content may be plain text files and you are using version
1587 3.0.2 or earlier) in your user.action file. And also, for any site or page
1588 where making any changes at all to the content is to be avoided.
1590 Privoxy does not do FTP at all, only HTTP and HTTPS (SSL) protocols, so please
1593 -------------------------------------------------------------------------------
1595 4.22. I just downloaded a Perl script, and Privoxy altered it! Yikes, what is
1600 -------------------------------------------------------------------------------
1602 4.23. Should I continue to use a "HOSTS" file for ad-blocking?
1604 One time-tested technique to defeat common ads is to trick the local DNS system
1605 by giving a phony IP address for the ad generator in the local HOSTS file,
1606 typically using 127.0.0.1, aka localhost. This effectively blocks the ad.
1608 There is no reason to use this technique in conjunction with Privoxy. Privoxy
1609 does essentially the same thing, much more elegantly and with much more
1610 flexibility. A large HOSTS file, in fact, not only duplicates effort, but may
1611 get in the way. It is recommended to remove such entries from your HOSTS file.
1612 If you think your hosts list is neglected by Privoxy's configuration, consider
1613 adding your list to your user.action file:
1618 ads.galore.example.com
1621 -------------------------------------------------------------------------------
1623 4.24. Where can I find more information about Privoxy and related issues?
1625 Other references and sites of interest to Privoxy users:
1627 http://www.privoxy.org/, the Privoxy Home page.
1629 http://www.privoxy.org/faq/, the Privoxy FAQ.
1631 http://sourceforge.net/projects/ijbswa/, the Project Page for Privoxy on
1634 http://config.privoxy.org/, the web-based user interface. Privoxy must be
1635 running for this to work. Shortcut: http://p.p/
1637 http://sourceforge.net/tracker/?group_id=11118&atid=460288, to submit "misses"
1638 and other configuration related suggestions to the developers.
1640 http://www.junkbusters.com/ht/en/cookies.html, an explanation how cookies are
1641 used to track web users.
1643 http://www.junkbusters.com/ijb.html, the original Internet Junkbuster.
1645 http://privacy.net/, a useful site to check what information about you is
1646 leaked while you browse the web.
1648 http://www.squid-cache.org/, a very popular caching proxy, which is often used
1649 together with Privoxy.
1651 http://tor.eff.org/, Tor can help anonymize web browsing, web publishing,
1652 instant messaging, IRC, SSH, and other applications.
1654 http://www.privoxy.org/developer-manual/, the Privoxy developer manual.
1656 -------------------------------------------------------------------------------
1658 4.25. I've noticed that Privoxy changes "Microsoft" to "MicroSuck"! Why are you
1659 manipulating my browsing?
1661 We're not. The text substitutions that you are seeing are disabled in the
1662 default configuration as shipped. You have either manually activated the "fun"
1663 filter which is clearly labeled "Text replacements for subversive browsing fun!
1664 " or you are using an older Privoxy version and have implicitly activated it by
1665 choosing the "Adventuresome" profile in the web-based editor. Please upgrade!
1667 -------------------------------------------------------------------------------
1671 5.1. I cannot connect to any websites. Or, I am getting "connection refused"
1672 message with every web page. Why?
1674 There are several possibilities:
1676 * Privoxy is not running. Solution: verify that Privoxy is installed
1677 correctly, has not crashed, and is indeed running. Look at Privoxy's logs
1678 to see what they say.
1680 * Or your browser is configured for a different port than what Privoxy is
1681 using. Solution: verify that Privoxy and your browser are set to the same
1682 port (listen-address).
1684 * Or if using a forwarding rule, you have a configuration problem or a
1685 problem with a host in the forwarding chain. Solution: temporarily alter
1686 your configuration and take the forwarders out of the equation.
1688 * Or you have a firewall that is interfering and blocking you. Solution: try
1689 disabling or removing the firewall as a simple test.
1691 -------------------------------------------------------------------------------
1693 5.2. Why am I getting a 503 Error (WSAECONNREFUSED) on every page?
1695 More than likely this is a problem with your TCP/IP networking. ZoneAlarm has
1696 been reported to cause this symptom -- even if not running! The solution is to
1697 either fight the ZA configuration, or uninstall ZoneAlarm, and then find
1698 something better behaved in its place. Other personal firewall type products
1699 may cause similar type problems if not configured correctly.
1701 -------------------------------------------------------------------------------
1703 5.3. I just added a new rule, but the steenkin ad is still getting through.
1706 If the ad had been displayed before you added its URL, it will probably be held
1707 in the browser's cache for some time, so it will be displayed without the need
1708 for any request to the server, and Privoxy will not be involved. Flush the
1709 browser's caches, and then try again.
1711 If this doesn't help, you probably have an error in the rule you applied. Try
1712 pasting the full URL of the offending ad into http://config.privoxy.org/
1713 show-url-info and see if it really matches your new rule. Blocking ads is like
1714 blocking spam: a lot of tinkering is required to stay ahead of the game. And
1715 remember you need to block the URL of the ad in question, which may be entirely
1716 different from the site URL itself. Most ads are hosted on different servers
1717 than the main site itself. If you right-click on the ad, you should be able to
1718 get all the relevant information you need. Alternately, you can find the
1719 correct URL by looking at Privoxy's logs.
1721 Below is a slightly modified real-life log snippet that originates with one
1722 requested URL: www.example.com (name of site was changed for this example, the
1723 number of requests is real). You can see in this the complexity of what goes
1724 into making up this one "page". There are eight different domains involved
1725 here, with thirty two separate URLs requested in all, making up all manner of
1726 images, Shockwave Flash, JavaScript, CSS stylesheets, scripts, and other
1727 related content. Some of this content is obviously "good" or "bad", but not
1728 all. Many of the more questionable looking requests, are going to outside
1729 domains that seem to be identifying themselves with suspicious looking names,
1730 making our job a little easier. Privoxy has "crunched" (meaning caught and
1731 BLOCKED) quite a few items in this example, but perhaps missed a few as well.
1733 Request: www.example.com/
1734 Request: www.example.com/favicon.ico
1735 Request: img.example.com/main.css
1736 Request: img.example.com/sr.js
1737 Request: example.betamarker.com/example.html
1738 Request: www.lik-sang.com/Banners/bestsellers/skyscraper.php?likref=BSellers
1739 Request: img.example.com/pb.png
1740 Request: www.google-analytics.com/urchin.js crunch!
1741 Request: www.advertising-department.com/ats/switch.ps.php?26856 crunch!
1742 Request: img.example.com/p.gif
1743 Request: www.popuptraffic.com/assign.php?l=example&mode=behind crunch!
1744 Request: www.popuptraffic.com/scripts/popup.php?hid=5c3cf&tmpl=PBa.tmpl crunch!
1745 Request: www.popuptraffic.com/assign.php?l=example crunch!
1746 Request: www.lik-sang.com/Banners/best_sellers/best_sellers.css
1747 Request: www.adtrak.net/adx.js crunch!
1748 Request: img.example.com/hbg.gif
1749 Request: img.example.com/example.jpg
1750 Request: img.example.com/mt.png
1751 Request: img.example.com/mm.png
1752 Request: img.example.com/mb.png
1753 Request: www.popuptraffic.com/scripts/popup.php?hid=a71b91fa5&tmpl=Ua.tmp crunch!
1754 Request: www.example.com/tracker.js
1755 Request: www.lik-sang.com/Banners/best_sellers/lsi_head.gif
1756 Request: www.adtrak.net/adjs.php?n=020548130&what=zone:61 crunch!
1757 Request: www.adtrak.net/adjs.php?n=463594413&what=zone:58&source=Ua crunch!
1758 Request: www.lik-sang.com/Banners/best_sellers/bottomani.swf
1759 Request: mmm.elitemediagroup.net/install.php?allowpop=no&popupmincook=0&allowsp2=1 crunch!
1760 Request: www.example.com/tracker.js?screen=1400x1050&win=962x693
1761 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=61 crunch!
1762 Request: 66.70.21.80/scripts/click.php?hid=5c3cf599a9efd0320d26&si
1763 Request: 66.70.21.80/img/pixel.gif
1764 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=58&source=Ua&block=86400 crunch!
1765 Request: 66.70.21.80/scripts/click.php?hid=a71b9f6504b0c5681fa5&si=Ua
1767 Despite 12 out of 32 requests being blocked, the page looked, and seemed to
1768 behave perfectly "normal" (minus some ads, of course).
1770 -------------------------------------------------------------------------------
1772 5.4. One of my favorite sites does not work with Privoxy. What can I do?
1774 First verify that it is indeed a Privoxy problem, by toggling off Privoxy
1775 through http://config.privoxy.org/toggle, and then shift-reloading the problem
1776 page (i.e. holding down the shift key while clicking reload. Alternatively,
1777 flush your browser's disk and memory caches).
1779 If the problem went away, we know we have a configuration related problem. Now
1780 go to http://config.privoxy.org/show-url-info and paste the full URL of the
1781 page in question into the prompt. See which actions are being applied to the
1782 URL, and which matches in which actions files are responsible for that. It
1783 might be helpful also to look at your logs for this site too, to see what else
1784 might be happening. Many sites are complex and require a number of related
1785 pages to help present their content. Look at what else might be used by the
1786 page in question, and what of that might be required. Now, armed with this
1787 information, go to http://config.privoxy.org/show-status and select the
1788 appropriate actions files for editing.
1790 You can now either look for a section which disables the actions that you
1791 suspect to cause the problem and add a pattern for your site there, or make up
1792 a completely new section for your site. In any case, the recommended way is to
1793 disable only the prime suspect, reload the problem page, and only if the
1794 problem persists, disable more and more actions until you have identified the
1795 culprit. You may or may not want to turn the other actions on again. Remember
1796 to flush your browser's caches in between any such changes!
1798 Alternately, if you are comfortable with a text editor, you can accomplish the
1799 same thing by editing the appropriate actions file. Probably the easiest way to
1800 deal with such problems when editing by hand is to add your site to a { fragile
1801 } section in user.action, which is an alias that turns off most "dangerous"
1802 actions, but is also likely to turn off more actions then needed, and thus
1803 lower your privacy and protection more than necessary,
1805 Troubleshooting actions is discussed in more detail in the User Manual
1806 appendix, Troubleshooting: the Anatomy of an Action. There is also an actions
1807 tutorial with general configuration information and examples.
1809 As a last resort, you can always see if your browser has a setting that will
1810 bypass the proxy setting for selective sites. Modern browsers can do this.
1812 -------------------------------------------------------------------------------
1814 5.5. After installing Privoxy, I have to log in every time I start IE. What
1817 This is a quirk that effects the installation of Privoxy, in conjunction with
1818 Internet Explorer and Internet Connection Sharing on Windows 2000 and Windows
1819 XP. The symptoms may appear to be corrupted or invalid DUN settings, or
1822 When setting up an NT based Windows system with Privoxy you may find that
1823 things do not seem to be doing what you expect. When you set your system up you
1824 will probably have set up Internet Connection Sharing (ICS) with Dial up
1825 Networking (DUN) when logged in with administrator privileges. You will
1826 probably have made this DUN connection available to other accounts that you may
1827 have set-up on your system. E.g. Mum or Dad sets up the system and makes
1828 accounts suitably configured for the kids.
1830 When setting up Privoxy in this environment you will have to alter the proxy
1831 set-up of Internet Explorer (IE) for the specific DUN connection on which you
1832 wish to use Privoxy. When you do this the ICS DUN set-up becomes user specific.
1833 In this instance you will see no difference if you change the DUN connection
1834 under the account used to set-up the connection. However when you do this from
1835 another user you will notice that the DUN connection changes to make available
1836 to "Me only". You will also find that you have to store the password under each
1839 The reason for this is that each user's set-up for IE is user specific. Each
1840 set-up DUN connection and each LAN connection in IE store the settings for each
1841 user individually. As such this enforces individual configurations rather than
1842 common ones. Hence the first time you use a DUN connection after re-booting
1843 your system it may not perform as you expect, and prompt you for the password.
1844 Just set and save the password again and all should be OK.
1846 [Thanks to Ray Griffith for this submission.]
1848 -------------------------------------------------------------------------------
1850 5.6. I cannot connect to any FTP sites. Privoxy is blocking me.
1852 Privoxy cannot act as a proxy for FTP traffic, so do not configure your browser
1853 to use Privoxy as an FTP proxy. The same is true for any protocol other than
1854 HTTP or HTTPS (SSL).
1856 Most browsers understand FTP as well as HTTP. If you connect to a site, with a
1857 URL like ftp://ftp.example.com, your browser is making an FTP connection, and
1858 not a HTTP connection. So while your browser may speak FTP, Privoxy does not,
1859 and cannot proxy such traffic.
1861 To complicate matters, some systems may have a generic "proxy" setting, which
1862 will enable various protocols, including both HTTP and FTP proxying! So it is
1863 possible to accidentally enable FTP proxying in these cases. And of course, if
1864 this happens, Privoxy will indeed cause problems since it does not know FTP.
1865 Newer version will give a sane error message if a FTP connection is attempted.
1866 Just disable the FTP setting and all will be well again.
1868 Will Privoxy ever proxy FTP traffic? Unlikely. There just is not much reason,
1869 and the work to make this happen is more than it may seem.
1871 -------------------------------------------------------------------------------
1873 5.7. In Mac OSX, I can't configure Microsoft Internet Explorer to use Privoxy
1876 Microsoft Internet Explorer (in versions like 5.1) respects system-wide network
1877 settings. In order to change the HTTP proxy, open System Preferences, and click
1878 on the Network icon. In the settings pane that comes up, click on the Proxies
1879 tab. Ensure the "Web Proxy (HTTP)" checkbox is checked and enter 127.0.0.1 in
1880 the entry field. Enter 8118 in the Port field. The next time you start IE, it
1881 should reflect these values.
1883 -------------------------------------------------------------------------------
1885 5.8. In Mac OSX, I dragged the Privoxy folder to the trash in order to
1886 uninstall it. Now the finder tells me I don't have sufficient privileges to
1889 Just dragging the Privoxy folder to the trash is not enough to delete it.
1890 Privoxy supplies an uninstall.command file that takes care of these details.
1891 Open the trash, drag the uninstall.command file out of the trash and
1892 double-click on it. You will be prompted for confirmation and the
1893 administration password.
1895 The trash may still appear full after this command; emptying the trash from the
1896 desktop should make it appear empty again.
1898 -------------------------------------------------------------------------------
1900 5.9. In Mac OSX Panther (10.3), images often fail to load and/or I experience
1901 random delays in page loading. I'm using localhost as my browser's proxy
1904 We believe this is due to an IPv6-related bug in OSX, but don't fully
1905 understand the issue yet. In any case, changing the proxy setting to 127.0.0.1
1906 instead of localhost works around the problem.
1908 -------------------------------------------------------------------------------
1910 5.10. I get a completely blank page at one site. "View Source" shows only:
1911 <html><body></body></html>. Without Privoxy the page loads fine.
1913 Chances are that the site suffers from a bug in PHP, which results in empty
1914 pages being sent if the client explicitly requests an uncompressed page, like
1915 Privoxy does. This bug has been fixed in PHP 4.2.3.
1917 To find out if this is in fact the source of the problem, try adding the site
1918 to a -prevent-compression section in user.action:
1920 # Make exceptions for ill-behaved sites:
1922 {-prevent-compression}
1925 If that works, you may also want to report the problem to the site's
1926 webmasters, telling them to use zlib.output_compression instead of ob_gzhandler
1927 in their PHP applications (workaround) or upgrade to PHP 4.2.3 or later (fix).
1929 -------------------------------------------------------------------------------
1931 5.11. My logs show many "Unable to get my own hostname" lines. Why?
1933 Privoxy tries to get the hostname of the system its running on from the IP
1934 address of the system interface it is bound to (from the config file
1935 listen-address setting). If the system cannot supply this information, Privoxy
1936 logs this condition.
1938 Typically, this would be considered a minor system configuration error. It is
1939 not a fatal error to Privoxy however, but may result in a much slower response
1940 from Privoxy on some platforms due to DNS timeouts.
1942 This can be caused by a problem with the local HOSTS file. If this file has
1943 been changed from the original, try reverting it to see if that helps. Make
1944 sure whatever name(s) are used for the local system, that they resolve both
1947 -------------------------------------------------------------------------------
1949 5.12. When I try to launch Privoxy, I get an error message "port 8118 is
1950 already in use" (or similar wording). Why?
1952 Port 8118 is Privoxy's default TCP "listening" port. Typically this message
1953 would mean that there is already one instance of Privoxy running, and your
1954 system is actually trying to start a second Privoxy on the same port, which
1955 will not work. (You can have multiple instances but they must be assigned
1956 different ports.) How and why this might happen varies from platform to
1957 platform, but you need to check your installation and start-up procedures.
1959 -------------------------------------------------------------------------------
1961 5.13. Pages with UTF-8 fonts are garbled.
1963 This is caused by the "demoronizer" filter. You should either upgrade Privoxy,
1964 or at least upgrade to the most recent default.action file available from
1965 SourceForge. Or you can simply disable the demoronizer filter.
1967 -------------------------------------------------------------------------------
1969 5.14. Why are binary files (such as images) corrupted when Privoxy is used?
1971 This may also be caused by the "demoronizer" filter, in conjunction with a web
1972 server that is misreporting a file type. Binary files are exempted from
1973 Privoxy's filtering (unless the web server by mistake says the file is
1974 something else). Either upgrade Privoxy, or go to the most recent
1975 default.action file available from SourceForge.
1977 -------------------------------------------------------------------------------
1979 5.15. What is the "demoronizer" and why is it there?
1981 The original demoronizer was a Perl script that cleaned up HTML pages which
1982 were created with certain Microsoft products. MS has used proprietary
1983 extensions to standardized font encodings (ISO 8859-1), which has caused
1984 problems for pages that are viewed with non-Microsoft products (and are
1985 expecting to see a standard set of fonts). The demoronizer corrected these
1986 errors so the pages displayed correctly. Privoxy borrowed from this script,
1987 introducing a filter based on the original demoronizer, which in turn could
1988 correct these errors on the fly.
1990 But this is only needed in some situations, and will cause serious problems in
1991 some other situations.
1993 If you are using Microsoft products, you do not need it. If you need to view
1994 pages with UTF-8 characters (such as Cyrillic or Chinese), then it will cause
1995 corruption of the fonts, and thus should not be on.
1997 On the other hand, if you use non-Microsoft products, and you occasionally
1998 notice wierd characters on pages, you might want to try it.
2000 -------------------------------------------------------------------------------
2002 5.16. Why do I keep seeing "PrivoxyWindowOpen()" in raw source code?
2004 Privoxy is attempting to disable malicious Javascript in this case, with the
2005 unsolicited-popups filter. Privoxy cannot tell very well "good" code snippets
2006 from "bad" code snippets.
2008 If you see this in HTML source, and the page displays without problems, then
2009 this is good, and likely some pop-up window was disabled. If you see this where
2010 it is causing a problem, such as a downloaded program source code file, then
2011 you should set an exception for this site or page such that the integrity of
2012 the page stays in tact by disabling all filtering.
2014 -------------------------------------------------------------------------------
2016 5.17. I am getting too many DNS errors like "404 No Such Domain". Why can't
2017 Privoxy do this better?
2019 There are potentially several factors here. First of all, the DNS resolution is
2020 done by the underlying operating system -- not Privoxy itself. Privoxy merely
2021 initiates the process and hands it off, and then later reports whatever the
2022 outcome was. And tries to give a coherent message if there seems to be a
2023 problem. In some cases, this might otherwise be mitigated by the browser itself
2024 which might try some work-arounds and alternate approaches (e.g adding "www."
2025 to the URL). In other cases, if Privoxy is being chained with another proxy,
2026 this could complicate the issue, and cause undue delays and timeouts. In the
2027 case of a "socks4a" proxy, the socks server handles all the DNS. Privoxy would
2028 just be the "messenger" which is reporting whatever problem occurred
2029 downstream, and not the root cause of the error.
2031 In any case, newer versions include various improvements to help Privoxy better
2034 -------------------------------------------------------------------------------
2036 5.18. At one site Privoxy just hangs, and starts taking all CPU. Why is this?
2038 This is probably a manifestation of the "100% cpu" problem that occurs on pages
2039 containing many (thousands upon thousands) of blank lines. The blank lines are
2040 in the raw HTML source of the page, and the browser just ignores them. But the
2041 pattern matching in Privoxy's page filtering mechanism is trying to match
2042 against absurdly long strings and this becomes very CPU-intensive, taking a
2043 long, long time to complete. Until a better solution comes along, disable
2044 filtering on these pages, particularly the js-annoyances and unsolicited-popups
2047 -------------------------------------------------------------------------------
2049 5.19. I just installed Privoxy, and all my browsing has slowed to a crawl. What
2052 This should not happen, and for the overwhelming number of users world-wide, it
2053 does not happen. I would suspect some inadvertent interaction of software
2054 components such as anti-virus software, spyware protectors, personal firewalls
2055 or similar components. Try disabling (or uninstalling) these one at a time and
2058 -------------------------------------------------------------------------------
2060 5.20. Why do my filters work on some sites but not on others?
2062 It's probably due to compression. It is a common practice for web servers to
2063 send their content "compressed" in order to speed things up, and then let the
2064 browser "uncompress" them. Privoxy does not (yet) support compression. But we
2065 can force the web server to bend to our will ;-) So for filtering, make sure
2066 you have prevent-compression turned ON!
2068 -------------------------------------------------------------------------------
2070 6. Contacting the developers, Bug Reporting and Feature Requests
2072 We value your feedback. In fact, we rely on it to improve Privoxy and its
2073 configuration. However, please note the following hints, so we can provide you
2074 with the best support:
2076 -------------------------------------------------------------------------------
2080 For casual users, our support forum at SourceForge is probably best suited:
2081 http://sourceforge.net/tracker/?group_id=11118&atid=211118
2083 All users are of course welcome to discuss their issues on the users mailing
2084 list, where the developers also hang around.
2086 -------------------------------------------------------------------------------
2088 6.2. Reporting Problems
2090 "Problems" for our purposes, come in two forms:
2092 * Configuration issues, such as ads that slip through, or sites that don't
2093 function properly due to one Privoxy "action" or another being turned "on".
2095 * "Bugs" in the programming code that makes up Privoxy, such as that might
2098 -------------------------------------------------------------------------------
2100 6.2.1. Reporting Ads or Other Configuration Problems
2102 Please send feedback on ads that slipped through, innocent images that were
2103 blocked, sites that don't work properly, and other configuration related
2104 problem of default.action file, to http://sourceforge.net/tracker/?group_id=
2105 11118&atid=460288, the Actions File Tracker.
2107 New, improved default.action files may occasionally be made available based on
2108 your feedback. These will be announced on the ijbswa-announce list and
2109 available from our the files section of our project page.
2111 -------------------------------------------------------------------------------
2113 6.2.2. Reporting Bugs
2115 Please report all bugs only through our bug tracker: http://sourceforge.net/
2116 tracker/?group_id=11118&atid=111118.
2118 Before doing so, please make sure that the bug has not already been submitted
2119 and observe the additional hints at the top of the submit form. If already
2120 submitted, please feel free to add any info to the original report that might
2121 help to solve the issue.
2123 Please try to verify that it is a Privoxy bug, and not a browser or site bug
2124 first. If unsure, try toggling off Privoxy, and see if the problem persists. If
2125 you are using your own custom configuration, please try the stock configs to
2126 see if the problem is configuration related.
2128 If not using the latest version, the bug may have been found and fixed in the
2129 meantime. We would appreciate if you could take the time to upgrade to the
2130 latest version (or even the latest CVS snapshot) and verify your bug.
2132 Please be sure to provide the following information:
2134 * The exact Privoxy version of the proxy software (if you got the source from
2135 CVS, please also provide the source code revisions as shown in http://
2136 config.privoxy.org/show-version).
2138 * The operating system and versions you run Privoxy on, (e.g. Windows XP
2139 SP2), if you are using a Unix flavor, sending the output of "uname -a"
2142 * The name, platform, and version of the browser you were using (e.g.
2143 Internet Explorer v5.5 for Mac).
2145 * The URL where the problem occurred, or some way for us to duplicate the
2146 problem (e.g. http://somesite.example.com/?somethingelse=123).
2148 * Whether your version of Privoxy is one supplied by the developers of
2149 Privoxy via SourceForge, or somewhere else.
2151 * Whether you are using Privoxy in tandem with another proxy such as Tor. If
2152 so, please try disabling the other proxy.
2154 * Whether you are using a personal firewall product. If so, does Privoxy work
2157 * Any other pertinent information to help identify the problem such as config
2158 or log file excerpts (yes, you should have log file entries for each action
2161 * Please provide your SF login, or email address, in case we need to contact
2164 The appendix of the Privoxy User Manual also has helpful information on
2165 understanding actions, and action debugging.
2167 -------------------------------------------------------------------------------
2169 6.3. Request New Features
2171 You are welcome to submit ideas on new features or other proposals for
2172 improvement through our feature request tracker at http://sourceforge.net/
2173 tracker/?atid=361118&group_id=11118.
2175 -------------------------------------------------------------------------------
2179 For any other issues, feel free to use the mailing lists. Technically
2180 interested users and people who wish to contribute to the project are also
2181 welcome on the developers list! You can find an overview of all Privoxy-related
2182 mailing lists, including list archives, at: http://sourceforge.net/mail/?
2185 -------------------------------------------------------------------------------
2187 7. Privoxy Copyright, License and History
2189 Copyright © 2001 - 2006 by Privoxy Developers <
2190 ijbswa-developers@lists.sourceforge.net>
2192 Some source code is based on code Copyright © 1997 by Anonymous Coders and
2193 Junkbusters, Inc. and licensed under the GNU General Public License.
2195 Portions of this document are "borrowed" from the original Junkbuster (tm) FAQ,
2196 and modified as appropriate for Privoxy.
2198 -------------------------------------------------------------------------------
2202 Privoxy is free software; you can redistribute it and/or modify it under the
2203 terms of the GNU General Public License, version 2, as published by the Free
2204 Software Foundation.
2206 This program is distributed in the hope that it will be useful, but WITHOUT ANY
2207 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
2208 PARTICULAR PURPOSE. See the GNU General Public License for more details, which
2209 is available from the Free Software Foundation, Inc, 51 Franklin Street, Fifth
2210 Floor, Boston, MA 02110-1301, USA
2212 You should have received a copy of the GNU General Public License along with
2213 this program; if not, write to the
2216 Foundation, Inc. 51 Franklin Street, Fifth Floor
2217 Boston, MA 02110-1301
2220 -------------------------------------------------------------------------------
2224 A long time ago, there was the Internet Junkbuster, by Anonymous Coders and
2225 Junkbusters Corporation. This saved many users a lot of pain in the early days
2226 of web advertising and user tracking.
2228 But the web, its protocols and standards, and with it, the techniques for
2229 forcing ads on users, give up autonomy over their browsing, and for tracking
2230 them, keeps evolving. Unfortunately, the Internet Junkbuster did not. Version
2231 2.0.2, published in 1998, was (and is) the last official release available from
2232 Junkbusters Corporation. Fortunately, it had been released under the GNU GPL,
2233 which allowed further development by others.
2235 So Stefan Waldherr started maintaining an improved version of the software, to
2236 which eventually a number of people contributed patches. It could already
2237 replace banners with a transparent image, and had a first version of pop-up
2238 killing, but it was still very closely based on the original, with all its
2239 limitations, such as the lack of HTTP/1.1 support, flexible per-site
2240 configuration, or content modification. The last release from this effort was
2241 version 2.0.2-10, published in 2000.
2243 Then, some developers picked up the thread, and started turning the software
2244 inside out, upside down, and then reassembled it, adding many new features
2247 The result of this is Privoxy, whose first stable version, 3.0, was released