Privoxy Frequently Asked Questions
-Copyright © 2001-2006 by Privoxy Developers
+[ Copyright 2001-2007 by Privoxy Developers ]
-$Id: faq.sgml,v 2.23 2006/10/21 22:19:52 hal9 Exp $
+$Id: faq.sgml,v 2.36 2008/01/17 01:49:51 hal9 Exp $
This FAQ gives quick answers to frequently asked questions about Privoxy. It is
not a substitute for the Privoxy User Manual.
What is Privoxy?
-Privoxy is a web proxy with advanced filtering capabilities for protecting
-privacy, modifying web page data, managing cookies, controlling access, and
-removing ads, banners, pop-ups and other obnoxious Internet junk. Privoxy has a
-very flexible configuration and can be customized to suit individual needs and
-tastes. Privoxy has application for both stand-alone systems and multi-user
-networks.
+Privoxy is a non-caching web proxy with advanced filtering capabilities for
+enhancing privacy, modifying web page data, managing HTTP cookies, controlling
+access, and removing ads, banners, pop-ups and other obnoxious Internet junk.
+Privoxy has a flexible configuration and can be customized to suit individual
+needs and tastes. Privoxy has application for both stand-alone systems and
+multi-user networks.
Privoxy is based on Internet Junkbuster (tm).
Please note that this document is a work in progress. This copy represents the
-state at the release of version 3.0.6. You can find the latest version of the
+state at the release of version 3.0.8. You can find the latest version of the
document at http://www.privoxy.org/faq/. Please see the Contact section if you
want to contact the developers.
Table of Contents
1. General Information
-
- 1.1. Who should use Privoxy?
+
+ 1.1. Who should give Privoxy a try?
1.2. Is Privoxy the best choice for me?
1.3. What is a "proxy"? How does Privoxy work?
1.4. Does Privoxy do anything more than ad blocking?
1.15. Can Privoxy remove spyware? Adware? Viruses?
1.16. Can I use Privoxy with other ad-blocking software?
1.17. I would like to help you, what can I do?
-
+
1.17.1. Would you like to participate?
1.17.2. Contribute!
1.17.3. Software
-
+
2. Installation
-
+
2.1. Which browsers are supported by Privoxy?
2.2. Which operating systems are supported?
2.3. Can I use Privoxy with my email client?
- 2.4. Can I install Privoxy over Junkbuster?
- 2.5. I just installed Privoxy. Is there anything special I have to do now?
- 2.6. What is the proxy address of Privoxy?
- 2.7. I just installed Privoxy, and nothing is happening. All the ads are
+ 2.4. I just installed Privoxy. Is there anything special I have to do now?
+ 2.5. What is the proxy address of Privoxy?
+ 2.6. I just installed Privoxy, and nothing is happening. All the ads are
there. What's wrong?
- 2.8. I get a "Privoxy is not being used" dummy page although Privoxy is
+ 2.7. I get a "Privoxy is not being used" dummy page although Privoxy is
running and being used.
-
+
3. Configuration
-
+
3.1. What exactly is an "actions" file?
3.2. The "actions" concept confuses me. Please list some of these
"actions".
3.13. Instead of ads, now I get a checkerboard pattern. I don't want to see
anything.
3.14. Why would anybody want to see a checkerboard pattern?
- 3.15. I see some images being replaced by a text instead of the
+ 3.15. I see some images being replaced with text instead of the
checkerboard image. Why and how do I get rid of this?
3.16. Can Privoxy run as a service on Win2K/NT/XP?
3.17. How can I make Privoxy work with other proxies like Squid or Tor?
3.18. Can I just set Privoxy to use port 80 and thus avoid individual
browser configuration?
3.19. Can Privoxy run as a "transparent" proxy?
- 3.20. How can I configure Privoxy for use with Outlook Express?
- 3.21. How can I have separate rules just for HTML mail?
- 3.22. I sometimes notice cookies sneaking through. How?
- 3.23. Are all cookies bad? Why?
- 3.24. How can I allow permanent cookies for my trusted sites?
- 3.25. Can I have separate configurations for different users?
- 3.26. Can I set-up Privoxy as a whitelist of "good" sites?
- 3.27. How can I turn off ad-blocking?
- 3.28. How can I have custom template pages, like the BLOCKED page?
- 3.29. How can I remove the "Go There Anyway" link from the BLOCKED page?
-
+ 3.20. Can Privoxy run as a "intercepting" proxy?
+ 3.21. How can I configure Privoxy for use with Outlook Express?
+ 3.22. How can I have separate rules just for HTML mail?
+ 3.23. I sometimes notice cookies sneaking through. How?
+ 3.24. Are all cookies bad? Why?
+ 3.25. How can I allow permanent cookies for my trusted sites?
+ 3.26. Can I have separate configurations for different users?
+ 3.27. Can I set-up Privoxy as a whitelist of "good" sites?
+ 3.28. How can I turn off ad-blocking?
+ 3.29. How can I have custom template pages, like the BLOCKED page?
+ 3.30. How can I remove the "Go There Anyway" link from the BLOCKED page?
+
4. Miscellaneous
-
+
4.1. How much does Privoxy slow my browsing down? This has to add extra
time to browsing.
- 4.2. I notice considerable delays in page requests compared to the old
- Junkbuster. What's wrong?
+ 4.2. I notice considerable delays in page requests. What's wrong?
4.3. What are "http://config.privoxy.org/" and "http://p.p/"?
4.4. How can I submit new ads, or report problems?
4.5. If I do submit missed ads, will they be included in future updates?
4.15. How can Privoxy filter Secure (HTTPS) URLs?
4.16. Privoxy runs as a "server". How secure is it? Do I need to take any
special precautions?
- 4.17. How can I temporarily disable Privoxy?
+ 4.17. Can I temporarily disable Privoxy?
4.18. When "disabled" is Privoxy totally out of the picture?
4.19. How can I tell Privoxy to totally ignore certain sites?
4.20. My logs show Privoxy "crunches" ads, but also its own internal CGI
4.24. Where can I find more information about Privoxy and related issues?
4.25. I've noticed that Privoxy changes "Microsoft" to "MicroSuck"! Why are
you manipulating my browsing?
-
+ 4.26. Does Privoxy produce "valid" HTML (or XHTML)?
+
5. Troubleshooting
-
+
5.1. I cannot connect to any websites. Or, I am getting "connection
refused" message with every web page. Why?
5.2. Why am I getting a 503 Error (WSAECONNREFUSED) on every page?
5.19. I just installed Privoxy, and all my browsing has slowed to a crawl.
What gives?
5.20. Why do my filters work on some sites but not on others?
-
+
6. Contacting the developers, Bug Reporting and Feature Requests
-
+
6.1. Get Support
6.2. Reporting Problems
-
+
6.2.1. Reporting Ads or Other Configuration Problems
6.2.2. Reporting Bugs
-
+
6.3. Request New Features
6.4. Other
-
+
7. Privoxy Copyright, License and History
-
+
7.1. License
7.2. History
-
+
1. General Information
-1.1. Who should use Privoxy?
+1.1. Who should give Privoxy a try?
-Anyone that is interested in security, privacy, or in finer-grained control
-over their web and Internet experience. Everyone is encouraged to try Privoxy.
+Anyone who is interested in security, privacy, or in finer-grained control over
+their web and Internet experience.
-------------------------------------------------------------------------------
1.2. Is Privoxy the best choice for me?
Privoxy is certainly a good choice, especially for those who want more control
-and security. Those that have the ability to fine-tune their installation will
-benefit the most. One of Privoxy's strength's is that it is highly configurable
-giving you the ability to completely personalize your installation. Being
-familiar with, or at least having an interest in learning about HTTP and other
-networking protocols, HTML, IP (Internet Protocol), and "Regular Expressions"
-will be a big plus and will help you get the most out of Privoxy. A new
-installation just includes a very basic configuration. The user should take
-this as a starting point only, and enhance it as he or she sees fit. In fact,
-the user is encouraged, and expected to, fine-tune the configuration.
+and security. Those with the willingness to read the documentation and the
+ability to fine-tune their installation will benefit the most.
+
+One of Privoxy's strengths is that it is highly configurable giving you the
+ability to completely personalize your installation. Being familiar with, or at
+least having an interest in learning about HTTP and other networking protocols,
+HTML, and "Regular Expressions" will be a big plus and will help you get the
+most out of Privoxy. A new installation just includes a very basic
+configuration. The user should take this as a starting point only, and enhance
+it as he or she sees fit. In fact, the user is encouraged, and expected to,
+fine-tune the configuration.
Much of Privoxy's configuration can be done with a Web browser. But there are
areas where configuration is done using a text editor to edit configuration
-files.
+files. Also note that the web-based action editor doesn't use authentication
+and should only be enabled in environments where all clients with access to
+Privoxy listening port can be trusted.
-------------------------------------------------------------------------------
1.5. What is this new version of "Junkbuster"?
-A long time ago, there was the Internet Junkbuster, by Anonymous Coders and
+A long time ago, there was the Internet Junkbuster, by Anonymous Coders and
Junkbusters Corporation. This saved many users a lot of pain in the early days
of web advertising and user tracking.
Privoxy picks up where Junkbuster left off. All the old features remain. The
new Privoxy still blocks ads and banners, still manages cookies, and still
-helps protect your privacy. But, these are all greatly enhanced, and many, many
-new features have been added, all in the same vein.
-
-The configuration has changed significantly as well. This is something that
-users will notice right off the bat if upgrading from Junkbuster 2.0.x. The
-"blocklist" "cookielist", "imagelist" and much more has been combined into the
-"actions" files, with a completely different syntax. See the What's New page
-for the latest updates.
+helps protect your privacy. But, most of these features have been enhanced, and
+many new ones have been added, all in the same vein.
Privoxy's new features include:
+ * Can be run as an "intercepting" proxy, which obviates the need to configure
+ browsers individually.
+
+ * Sophisticated actions and filters for manipulating both server and client
+ headers.
+
+ * Can be chained with other proxies.
+
* Integrated browser based configuration and control utility at http://
config.privoxy.org/ (shortcut: http://p.p/). Browser-based tracing of rule
and filter effects. Remote toggling.
-
+
* Web page filtering (text replacements, removes banners based on size,
- invisible "web-bugs", JavaScript and HTML annoyances, pop-up windows,
- header manipulation, etc.)
-
+ invisible "web-bugs", JavaScript and HTML annoyances, pop-up windows, etc.)
+
* Modularized configuration that allows for standard settings and user
settings to reside in separate files, so that installing updated actions
files won't overwrite individual user settings.
-
- * HTTP/1.1 compliant (but not all optional 1.1 features are supported).
-
+
* Support for Perl Compatible Regular Expressions in the configuration files,
- and generally a more sophisticated and flexible configuration syntax over
- previous versions.
-
+ and a more sophisticated and flexible configuration syntax.
+
* Improved cookie management features (e.g. session based cookies).
-
+
* GIF de-animation.
-
+
* Bypass many click-tracking scripts (avoids script redirection).
-
+
* Multi-threaded (POSIX and native threads).
-
+
* User-customizable HTML templates for all proxy-generated pages (e.g.
"blocked" page).
-
+
* Auto-detection and re-reading of config file changes.
-
+
* Improved signal handling, and a true daemon mode (Unix).
-
+
* Every feature now controllable on a per-site or per-location basis,
configuration more powerful and versatile over-all.
-
+
* Many smaller new features added, limitations and bugs removed, and security
holes fixed.
-
+
-------------------------------------------------------------------------------
1.8. How does Privoxy know what is an ad, and what is not?
1.10. Will I have to configure Privoxy before I can use it?
-No, not really. The default installation should give you a good starting point,
-and block most ads and unwanted content. Many of the more advanced features are
-off by default, and would require you to activate them.
+That depends on your expectations. The default installation should give you a
+good starting point, and block most ads and unwanted content, but many of the
+more advanced features are off by default, and require you to activate them.
You do have to set up your browser to use Privoxy (see the Installation section
below).
And you will certainly run into situations where there are false positives, or
ads not being blocked that you may not want to see. In these cases, you would
certainly benefit by customizing Privoxy's configuration to more closely match
-your individual situation. And we would encourage you to do this. This is where
-the real power of Privoxy lies!
+your individual situation. And we encourage you to do this. This is where the
+real power of Privoxy lies!
-------------------------------------------------------------------------------
all?
Modern browsers do indeed have some of the same functionality as Privoxy. Maybe
-this is adequate for you. But Privoxy is much more versatile and powerful, and
-can do a number of things that browsers just can't.
+this is adequate for you. But Privoxy is very versatile and powerful, and can
+probably do a number of things your browser just can't.
In addition, a proxy is good choice if you use multiple browsers, or have a LAN
with multiple computers since Privoxy can run as a server application. This way
all the configuration is in one place, and you don't have to maintain a similar
configuration for possibly many browsers or users.
+Note, however, that it's recommended to leverage both your browser's and
+Privoxy's privacy enhancing features at the same time. While your browser
+probably lacks some features Privoxy offers, it should also be able to do some
+things more reliable, for example restricting and suppressing JavaScript.
+
-------------------------------------------------------------------------------
1.13. Why should I trust Privoxy?
The most important reason is because you have access to everything, and you can
control everything. You can check every line of every configuration file
yourself. You can check every last bit of source code should you desire. And
-even if you can't read code, there should be some comfort in knowing that
-thousands of other people can, and do read it. You can build the software from
-scratch, if you want, so that you know the executable is clean, and that it is
-yours. In fact, we encourage this level of scrutiny. It is one reason we use
-Privoxy ourselves.
+even if you can't read code, there should be some comfort in knowing that other
+people can, and do read it. You can build the software from scratch, if you
+want, so that you know the executable is clean, and that it is yours. In fact,
+we encourage this level of scrutiny. It is one reason we use Privoxy ourselves.
-------------------------------------------------------------------------------
1.14. Is there is a license or fee? What about a warranty? Registration?
-Privoxy is licensed under the GNU General Public License (GPL). It is free to
-use, copy, modify or distribute as you wish under the terms of this license.
-Please see the Copyright section for more information on the license and
-copyright. Or the LICENSE file that should be included.
+Privoxy is free software and licensed under the GNU General Public License
+(GPL) version 2. It is free to use, copy, modify or distribute as you wish
+under the terms of this license. Please see the Copyright section for more
+information on the license and copyright. Or the LICENSE file that should be
+included.
There is no warranty of any kind, expressed, implied or otherwise. That is
something that would cost real money ;-) There is no registration either.
-Privoxy really is free in every respect!
-------------------------------------------------------------------------------
1.15. Can Privoxy remove spyware? Adware? Viruses?
-No. Privoxy cannot remove anything. It is not a removal tool. It is a
-preventative. Privoxy can help prevent contact from sites that use such tactics
+No, at least not reliably enough to trust it. Privoxy is not designed to be a
+malware removal tool and the default configuration doesn't even try to filter
+out any malware.
+
+Privoxy could help prevent contact from (known) sites that use such tactics
with appropriate configuration rules, and thus could conceivably prevent
-contamination from such sites.
+contamination from such sites. However, keeping such a configuration up to date
+would require a lot of time and effort that would be better spend on keeping
+your software itself up to date so it doesn't have known vulnerabilities.
-------------------------------------------------------------------------------
But it is probably not necessary to use Privoxy in conjunction with other
ad-blocking products, and this could conceivably cause undesirable results. It
-would be better to choose one software or the other and work a little to tweak
+might be better to choose one software or the other and work a little to tweak
its configuration to your liking.
+Note that this is an advice specific to ad blocking.
+
-------------------------------------------------------------------------------
1.17. I would like to help you, what can I do?
mundane things that need to be done, like checking the Tracker feedback
sections.
-So first thing, get an account on SourceForge.net and mail your id to the
+So first thing, get an account on SourceForge.net and mail your id to the
developers mailing list. Then, please read the Developer's Manual, at least the
pertinent sections.
+You can also start helping out without SourceForge.net account, simply by
+showing up on the mailing list, helping out other users, providing general
+feedback or reporting problems you noticed.
+
-------------------------------------------------------------------------------
1.17.2. Contribute!
We, of course, welcome donations and could use money for domain registering,
buying software to test Privoxy with, and, of course, for regular world-wide
get-togethers (hahaha). If you enjoy the software and feel like helping us with
-a donation, just drop us a note.
+a donation, just drop us a note and get your name on the list of contributors.
-------------------------------------------------------------------------------
2.1. Which browsers are supported by Privoxy?
Any browser that can be configured to use a proxy, which should be virtually
-all browsers, including Firefox, Internet Explorer, and Opera among others.
-Direct browser support is not an absolute requirement since Privoxy runs as a
-separate application and talks to the browser in the standardized HTTP
-protocol, just like a web server does.
+all browsers, including Firefox, Internet Explorer, Opera, and Safari among
+others. Direct browser support is not an absolute requirement since Privoxy
+runs as a separate application and talks to the browser in the standardized
+HTTP protocol, just like a web server does.
-------------------------------------------------------------------------------
2.2. Which operating systems are supported?
-At present, Privoxy is known to run on Windows(95, 98, ME, 2000, XP), Linux
-(RedHat, SuSE, Debian, Fedora, Gentoo, Slackware and others), Mac OSX, OS/2,
-AmigaOS, FreeBSD, NetBSD, OpenBSD, Solaris, and various other flavors of Unix.
+At present, Privoxy is known to run on Windows(95, 98, ME, 2000, XP, Vista),
+GNU/Linux (RedHat, SuSE, Debian, Fedora, Gentoo, Slackware and others), Mac
+OSX, OS/2, AmigaOS, FreeBSD, NetBSD, OpenBSD, Solaris, and various other
+flavors of Unix.
But any operating system that runs TCP/IP, can conceivably take advantage of
Privoxy in a networked situation where Privoxy would run as a server on a LAN
-------------------------------------------------------------------------------
-2.4. Can I install Privoxy over Junkbuster?
+2.4. I just installed Privoxy. Is there anything special I have to do now?
-We recommend you un-install Junkbuster first to minimize conflicts and
-confusion. You may want to save your old configuration files for future
-reference. The configuration files and syntax have substantially changed, so
-you will need to manually port your old patterns. See the note to upgraders and
-installation chapter in the User Manual for details.
-
-Note: Some installers may automatically un-install Junkbuster, if present!
-
--------------------------------------------------------------------------------
-
-2.5. I just installed Privoxy. Is there anything special I have to do now?
-
-All browsers must be told to use Privoxy as a proxy by specifying the correct
+All browsers should be told to use Privoxy as a proxy by specifying the correct
proxy address and port number in the appropriate configuration area for the
-browser. See the User Manual for more details. You should also flush your
-browser's memory and disk cache to get rid of any cached junk items, and remove
-any stored cookies.
+browser. It's possible to combine Privoxy with a packet filter to intercept
+HTTP requests even if the client isn't explicitly configured to use Privoxy,
+but where possible, configuring the client is recommended. See the User Manual
+for more details. You should also flush your browser's memory and disk cache to
+get rid of any cached junk items, and remove any stored cookies.
-------------------------------------------------------------------------------
-2.6. What is the proxy address of Privoxy?
+2.5. What is the proxy address of Privoxy?
If you set up the Privoxy to run on the computer you browse from (rather than
your ISP's server or some networked computer on a LAN), the proxy will be on
127.0.0.1 (sometimes referred to as "localhost", which is the special name used
by every computer on the Internet to refer to itself) and the port will be 8118
-(unless you have Privoxy to run on a different port with the listen-address
-config option).
+(unless you used the listen-address config option to tell Privoxy to run on a
+different port).
When configuring your browser's proxy settings you typically enter the word
"localhost" or the IP address "127.0.0.1" in the boxes next to "HTTP" and
above. Note that Privoxy doesn't listen on any LAN interfaces by default.
Privoxy does not currently handle any other protocols such as FTP, SMTP, IM,
-IRC, ICQ, etc. Be sure that proxying any of these other protocols is not
-activated.
+IRC, ICQ, etc.
-------------------------------------------------------------------------------
-2.7. I just installed Privoxy, and nothing is happening. All the ads are there.
+2.6. I just installed Privoxy, and nothing is happening. All the ads are there.
What's wrong?
Did you configure your browser to use Privoxy as a proxy? It does not sound
-------------------------------------------------------------------------------
-2.8. I get a "Privoxy is not being used" dummy page although Privoxy is running
+2.7. I get a "Privoxy is not being used" dummy page although Privoxy is running
and being used.
-First, make sure that Privoxy is really running and being used by visiting
+First, make sure that Privoxy is really running and being used by visiting
http://p.p/. You should see the Privoxy main page. If not, see the chapter on
starting Privoxy in the User Manual.
The procedure for clearing the cache varies from browser to browser. For
example, Mozilla/Netscape users would click Edit --> Preferences --> Advanced
---> Cache and then click both "Clear Memory Cache" and "Clear Disk Cache". And,
-Firefox users would click Tools --> Options --> Privacy --> Cache and then
-click "Clear Cache Now".
+--> Cache and then click both "Clear Memory Cache" and "Clear Disk Cache". In
+some Firefox versions it's Tools --> Options --> Privacy --> Cache and then
+click "Clear Cache Now".
-------------------------------------------------------------------------------
Actions can be defined on a URL pattern basis, i.e. for single URLs, whole web
sites, groups or parts thereof etc. Actions can also be grouped together and
then applied to requests matching one or more patterns. There are many possible
-actions that might apply to any given site. As an example, if you are blocking
+actions that might apply to any given site. As an example, if you are blocking
cookies as one of your default actions, but need to accept cookies from a given
site, you would need to define an exception for this site in one of your
actions files, preferably in user.action.
3.2. The "actions" concept confuses me. Please list some of these "actions".
-For a comprehensive discussion of the actions concept, please refer to the
+For a comprehensive discussion of the actions concept, please refer to the
actions file chapter in the User Manual. It includes a list of all actions and
an actions file tutorial to get you started.
Actions files are just text files in a special syntax and can be edited with a
text editor. But probably the easiest way is to access Privoxy's user interface
with your web browser at http://config.privoxy.org/ (Shortcut: http://p.p/) and
-then select "View & change the current configuration" from the menu.
+then select "View & change the current configuration" from the menu. Note that
+this feature must be explicitly enabled in the main config file (see
+enable-edit-actions).
-------------------------------------------------------------------------------
3.6. Can I use my old config files?
-The syntax and purpose of configuration files has remained the same throughout
-the 3.x series. Although each release contains updated, "improved" versions and
-it is recommended to use the newer configuration files. If upgrading from
-version prior to 3.0.4 the syntax for fast-redirects has changed. See the
-What's New section of the User Manual for details.
-
-But all configuration files have substantially changed from the Junkbuster
-days, and early versions of Privoxy 2.x. The old files, like blocklist will not
-work at all.
-
-Refer to the What's New page for information on configuration changes that may
-occur from one release to another.
+The syntax and purpose of configuration files has remained roughly the same
+throughout the 3.x series, but backwards compatibility is not guaranteed. Also
+each release contains updated, "improved" versions and it is therefore strongly
+recommended to install the newer configuration files and merge back your
+modifications.
-------------------------------------------------------------------------------
turn off all cookie handling for them in the user.action file. An example for
yahoo might look like:
-# Allow all cookies for Yahoo login:
-#
-{ -crunch-incoming-cookies -crunch-outgoing-cookies -session-cookies-only }
-.login.yahoo.com
+# Allow all cookies for Yahoo login:
+#
+{ -crunch-incoming-cookies -crunch-outgoing-cookies -session-cookies-only }
+.login.yahoo.com
+
These kinds of sites are often quite complex and heavy with Javascript and thus
"fragile". So if still a problem, we have an alias just for such sticky
situations:
-# Gmail is a _fragile_ site:
-#
-{ fragile }
- # Gmail is ...
- mail.google.com
+# Gmail is a _fragile_ site:
+#
+{ fragile }
+ # Gmail is ...
+ mail.google.com
+
Be sure to flush your browser's caches whenever making these kinds of changes,
just to make sure the changes "take".
"privoxy", with only 644 permissions.
When you use the browser-based editor, Privoxy itself is writing to the config
-files. Because Privoxy is running as the user "privoxy", it can update the
+files. Because Privoxy is running as the user "privoxy", it can update its own
config files.
-If you run Privoxy for multiple untrusted users (e.g. in a LAN), you will
-probably want to turn the web-based editor and remote toggle features off by
-setting "enable-edit-actions 0" and "enable-remote-toggle 0" in the main
-configuration file.
+If you run Privoxy for multiple untrusted users (e.g. in a LAN) or aren't
+entirely in control of your own browser, you will probably want to make sure
+that the the web-based editor and remote toggle features are "off" by setting "
+enable-edit-actions 0" and "enable-remote-toggle 0" in the main configuration
+file.
-Note that in the default configuration, only local users (i.e. those on
-"localhost") can connect to Privoxy, so this is not (normally) a security
-problem.
+As of Privoxy 3.0.7 these options are disabled by default.
-------------------------------------------------------------------------------
The default.filter file is where filters as supplied by the developers are
defined. Filters are a special subset of actions that can be used to modify or
-remove, web page content on the fly. Filters apply to anything in the page
-source (and optionally both client and server headers), including HTML tags,
-and JavaScript. Regular expressions are used to accomplish this. There are a
-number of pre-defined filters to deal with common annoyances. The filters are
-only defined here, to invoke them, you need to use the filter action in one of
-the actions files. Filtering is automatically disabled for inappropriate MIME
-types.
+remove web page content or headers on the fly. Content filters can be applied
+to anything in the page source, header filters can be applied to either server
+or client headers. Regular expressions are used to accomplish this.
+
+There are a number of pre-defined filters to deal with common annoyances. The
+filters are only defined here, to invoke them, you need to use the filter
+action in one of the actions files. Content filtering is automatically disabled
+for inappropriate MIME types, but if you now better than Privoxy what should or
+should not be filtered you can filter any content you like.
+
+Filters should not be confused with blocks, which is a completely different
+action, and is more typically used to block ads and unwanted sites.
If you are familiar with regular expressions, and HTML, you can look at the
provided default.filter with a text editor and define your own filters. This is
There is no GUI editor option for this part of the configuration, but you can
disable/enable the various pre-defined filters of the included default.filter
-file with the web-based actions file editor.
+file with the web-based actions file editor. Note that the custom actions
+editor must be explicitly enabled in the main config file (see
+enable-edit-actions).
+
+If you intend to develop your own filters, you might want to have a look at
+Privoxy-Filter-Test.
-------------------------------------------------------------------------------
is 192.168.1.1 and you wish to run Privoxy on port 8118, this line should look
like:
- listen-address 192.168.1.1:8118
+ listen-address 192.168.1.1:8118
+
Save the file, and restart Privoxy. Configure all browsers on the network then
to use this address and port number.
Alternately, you can have Privoxy listen on all available interfaces:
- listen-address :8118
+ listen-address :8118
+
And then use Privoxy's permit-access feature to limit connections. A firewall
in this situation is recommended as well.
URLs match both a handle-as-image and block action.
If you want to see nothing, then change the set-image-blocker action to
-"blank". This can be done by editing the user.action file, or through the
+"blank". This can be done by editing the user.action file, or through the
web-based actions file editor.
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
-3.15. I see some images being replaced by a text instead of the checkerboard
+3.15. I see some images being replaced with text instead of the checkerboard
image. Why and how do I get rid of this?
This happens when the banners are not embedded in the HTML code of the page
configuration?
No, its more complicated than that. This only works with special kinds of
-proxies known as "transparent" proxies (see below).
+proxies known as "intercepting" proxies (see below).
-------------------------------------------------------------------------------
3.19. Can Privoxy run as a "transparent" proxy?
-No, Privoxy currently does not have this ability, though it may be added in a
-future release. Transparent proxies require special handling of the request
-headers beyond what Privoxy is now capable of.
+The whole idea of Privoxy is to modify client requests and server responses in
+all sorts of ways and therefore it's not a transparent proxy as described in
+RFC 2616.
-Chaining Privoxy behind another proxy that has this ability should work though.
-See the forwarding chapter in the User Manual. As a transparent proxy to be
-used for chaining we suggest Transproxy (http://transproxy.sourceforge.net/).
+However, some people say "transparent proxy" when they mean "intercepting
+proxy". If you are one of them, please read the next entry.
-------------------------------------------------------------------------------
-3.20. How can I configure Privoxy for use with Outlook Express?
+3.20. Can Privoxy run as a "intercepting" proxy?
+
+Privoxy can't intercept traffic itself, but it can handle requests that where
+intercepted and redirected with a packet filter (like PF or iptables), as long
+as the Host header is present.
+
+As the Host header is required by HTTP/1.1 and as most web sites rely on it
+anyway, this limitation shouldn't be a problem.
+
+Please refer to your packet filter's documentation to learn how to intercept
+and redirect traffic into Privoxy. Afterward you just have to configure Privoxy
+to accept intercepted requests.
+
+-------------------------------------------------------------------------------
+
+3.21. How can I configure Privoxy for use with Outlook Express?
Outlook Express uses Internet Explorer components to both render HTML, and
fetch any HTTP requests that may be embedded in an HTML email. So however you
-------------------------------------------------------------------------------
-3.21. How can I have separate rules just for HTML mail?
+3.22. How can I have separate rules just for HTML mail?
The short answer is, you can't. Privoxy has no way of knowing which particular
application makes a request, so there is no way to distinguish between web
-------------------------------------------------------------------------------
-3.22. I sometimes notice cookies sneaking through. How?
+3.23. I sometimes notice cookies sneaking through. How?
Cookies can be set in several ways. The classic method is via the Set-Cookie
HTTP header. This is straightforward, and an easy one to manipulate, such as
-------------------------------------------------------------------------------
-3.23. Are all cookies bad? Why?
+3.24. Are all cookies bad? Why?
No, in fact there are many beneficial uses of cookies. Cookies are just a
method that browsers can use to store data between pages, or between browser
advantage of this layer of trust, and using the data they glean from you and
your browsing habits for their own purposes, and maybe to your potential
detriment. Such sites are using you and storing their data on your system. That
-is why the security conscious watch from whom those cookies come, and why they
+is why the privacy conscious watch from whom those cookies come, and why they
really need to be there.
See the Wikipedia cookie definition for more.
-------------------------------------------------------------------------------
-3.24. How can I allow permanent cookies for my trusted sites?
+3.25. How can I allow permanent cookies for my trusted sites?
There are several actions that relate to cookies. The default behavior is to
allow only "session cookies", which means the cookies only last for the current
browser session. This eliminates most kinds of abuse related to cookies. But
-there may be cases where we want cookies to last.
+there may be cases where you want cookies to last.
To disable all cookie actions, so that cookies are allowed unrestricted, both
in and out, for example.com:
- { -crunch-incoming-cookies -crunch-outgoing-cookies -session-cookies-only -filter{content-cookies} }
- .example.com
+ { -crunch-incoming-cookies -crunch-outgoing-cookies -session-cookies-only -filter{content-cookies} }
+ .example.com
-Place the above in user.action. Note some of these may be off by default
+
+Place the above in user.action. Note that some of these may be off by default
anyway, so this might be redundant, but there is no harm being explicit in what
you want to happen. user.action includes an alias for this situation, called
allow-all-cookies.
-------------------------------------------------------------------------------
-3.25. Can I have separate configurations for different users?
+3.26. Can I have separate configurations for different users?
Each instance of Privoxy has its own configuration, including such attributes
as the TCP port that it listens on. What you can do is run multiple instances
-------------------------------------------------------------------------------
-3.26. Can I set-up Privoxy as a whitelist of "good" sites?
+3.27. Can I set-up Privoxy as a whitelist of "good" sites?
Sure. There are a couple of things you can do for simple white-listing. Here's
one real easy one:
- ############################################################
- # Blacklist
- ############################################################
- { +block }
- / # Block *all* URLs
-
- ############################################################
- # Whitelist
- ############################################################
- { -block }
- kids.example.com
- toys.example.com
- games.example.com
+ ############################################################
+ # Blacklist
+ ############################################################
+ { +block }
+ / # Block *all* URLs
+
+ ############################################################
+ # Whitelist
+ ############################################################
+ { -block }
+ kids.example.com
+ toys.example.com
+ games.example.com
+
This allows access to only those three sites by first blocking all URLs, and
then subsequently allowing three specific exceptions.
-A more interesting approach is Privoxy's trustfile concept, which incorporates
-the notion of "trusted referrers". See the User Manual Trust documentation.
+Another approach is Privoxy's trustfile concept, which incorporates the notion
+of "trusted referrers". See the Trust documentation for details.
These are fairly simple approaches and are not completely foolproof. There are
various other configuration options that should be disabled (described
-------------------------------------------------------------------------------
-3.27. How can I turn off ad-blocking?
+3.28. How can I turn off ad-blocking?
-Ad blocking is achieved through a complex application of various Privoxy
+Ad blocking is achieved through a complex application of various Privoxy
actions. These actions are deployed against simple images, banners, flash
animations, text pages, JavaScript, pop-ups and pop-unders, etc., so its not as
simple as just turning one or two actions off. The various actions that make up
the additional blocks that are done for privacy reasons, you can very easily
over-ride all blocking with the following very simple rule in your user.action:
- # Unblock everybody, everywhere
- { -block }
- / # UN-Block *all* URLs
+ # Unblock everybody, everywhere
+ { -block }
+ / # UN-Block *all* URLs
+
Or even a more comprehensive reversing of various ad related actions:
- # Unblock everybody, everywhere, and turn off appropriate filtering, etc
- { -block \
- -filter{banners-by-size} \
- -filter{banners-by-link} \
- allow-popups \
- }
- / # UN-Block *all* URLs and allow ads
+ # Unblock everybody, everywhere, and turn off appropriate filtering, etc
+ { -block \
+ -filter{banners-by-size} \
+ -filter{banners-by-link} \
+ allow-popups \
+ }
+ / # UN-Block *all* URLs and allow ads
+
This last "action" in this compound statement, allow-popups, is an alias that
disables various pop-up blocking features.
-------------------------------------------------------------------------------
-3.28. How can I have custom template pages, like the BLOCKED page?
+3.29. How can I have custom template pages, like the BLOCKED page?
Privoxy "templates" are specialized text files utilized by Privoxy for various
purposes and can easily be modified using any text editor. All the template
pages are installed in a sub-directory appropriately named: templates. Knowing
-something about HTML syntax will of course be helpful. You cannot rename any of
-these files, or create completely new templates, that is not possible. But you
-can change the page content to whatever you like. Be forewarned that these
-files are subject to being overwritten during upgrades, so be sure to save any
-customizations.
+something about HTML syntax will of course be helpful.
+
+Be forewarned that the default templates are subject to being overwritten
+during upgrades. You can, however, create completely new templates, place them
+in another directory and specify the alternate path in the main config. For
+details, have a look at the templdir option.
-------------------------------------------------------------------------------
-3.29. How can I remove the "Go There Anyway" link from the BLOCKED page?
+3.30. How can I remove the "Go There Anyway" link from the BLOCKED page?
+
+There is more than one way to do it (although Perl is not involved).
Editing the BLOCKED template page (see above) may dissuade some users, but this
-method is easily circumvented. Where you need this level of control, you should
-build Privoxy from source, and enable various features that are available as
-compile-time options. You should configure the sources as follows:
+method is easily circumvented. Where you need this level of control, you might
+want to build Privoxy from source, and disable various features that are
+available as compile-time options. You should configure the sources as follows:
+
+ ./configure --disable-toggle --disable-editor --disable-force
- ./configure --disable-toggle --disable-editor --disable-force
This will create an executable with hard-coded security features so that
Privoxy does not allow easy bypassing of blocked sites, or changing the current
-configuration via any connected user's web browser. Some of these features can
-also be toggled on/off via options in Privoxy's main config file. But
-compiled-in compliance is a much better method of ensuring that a block is
-really a block.
+configuration via any connected user's web browser.
-Default builds of Privoxy are typically built with these features disabled.
+Finally, all of these features can also be toggled on/off via options in
+Privoxy's main config file which means you don't have to recompile anything.
-------------------------------------------------------------------------------
retrieved and displayed. The actual processing time required by Privoxy itself
for each page, is relatively small in the overall scheme of things, and happens
very quickly. This is typically more than offset by time saved not downloading
-and rendering ad images (if ad blocking is being used).
+and rendering ad images and other junk content (if ad blocking is being used).
-"Filtering" content via the filter or deanimate-gifs actions will certainly
-cause a perceived slowdown, since the entire document needs to be buffered
-before displaying. And on very large documents, filtering may have some
-measurable impact. How much depends on the page size, the actual definition of
-the filter(s), etc. See below. Most other actions have little to no impact on
-speed.
+"Filtering" content via the filter or deanimate-gifs actions may cause a
+perceived slowdown, since the entire document needs to be buffered before
+displaying. And on very large documents, filtering may have some measurable
+impact. How much depends on the page size, the actual definition of the filter
+(s), etc. See below. Most other actions have little to no impact on speed.
-Also, when filtering is enabled, typically there is a disabling of compression,
-(see prevent-compression). This can have an impact on speed as well. Again, the
-page size, etc. will determine how much of an impact.
+Also, when filtering is enabled but zlib support isn't available, compression
+is often disabled (see prevent-compression). This can have an impact on speed
+as well, although it's probably smaller than you might think. Again, the page
+size, etc. will determine how much of an impact.
-------------------------------------------------------------------------------
-4.2. I notice considerable delays in page requests compared to the old
-Junkbuster. What's wrong?
+4.2. I notice considerable delays in page requests. What's wrong?
If you use any filter action, such as filtering banners by size, web-bugs etc,
or the deanimate-gifs action, the entire document must be loaded into memory in
if the web server mis-reports the MIME type, then content that should not be
filtered, could be. Privoxy only knows how to differentiate filterable content
because of the MIME type as reported by the server, or because of some
-configuration setting that enables/disables filtering.
+configuration setting that enables/disables filtering.
-------------------------------------------------------------------------------
not be intercepted, and you have accessed the real web site at
config.privoxy.org.
-With recent versions of Privoxy (version 2.9.x and later), the user interface
-features information on the run time status, the configuration, and even a
-built-in editor for the actions files.
-
-Note that the built-in URLs from earlier versions of Junkbuster / Privoxy,
-http://example.com/show-proxy-args and http://i.j.b/, are no longer supported.
-If you still use such an old version, you should really consider upgrading to
-3.0.6.
-
-------------------------------------------------------------------------------
4.4. How can I submit new ads, or report problems?
There are many publicly usable "anonymous" proxies out there, which provide a
further level of indirection between you and the web server.
-However, these proxies are called "anonymous" because you don't need a
-password, not because they would offer any real anonymity. Most of them will
-log your IP address and make it available to the authorities in case you
+However, these proxies are called "anonymous" because you don't need to
+authenticate, not because they would offer any real anonymity. Most of them
+will log your IP address and make it available to the authorities in case you
violate the law of the country they run in. In fact you can't even rule out
that some of them only exist to *collect* information on (those suspicious)
people with a more than average preference for privacy.
-Your best bet is to chain Privoxy with Tor, an EFF supported onion routing
-system. The configuration details can be found in How do I use Privoxy together
-with Tor section just below.
+If you want to hide your IP address from most adversaries, you should consider
+chaining Privoxy with Tor. The configuration details can be found in How do I
+use Privoxy together with Tor section just below.
-------------------------------------------------------------------------------
4.8. Can Privoxy guarantee I am anonymous?
-No. Your chances of remaining anonymous are greatly improved, but unless you
-chain Privoxy with Tor or a similar system and know what you're doing when it
-comes to configuring the rest of your system, it would be safest to assume that
-everything you do on the Web can be traced back to you.
+No. Your chances of remaining anonymous are improved, but unless you chain
+Privoxy with Tor or a similar proxy and know what you're doing when it comes to
+configuring the rest of your system, you should assume that everything you do
+on the Web can be traced back to you.
Privoxy can remove various information about you, and allows you more freedom
to decide which sites you can trust, and what details you want to reveal. But
find out who you are, even if you are using a strict Privoxy configuration and
chained it with Tor.
-Most of Privoxy's protection can be easily subverted by an insecure browser
-configuration, therefore you should use a browser that can be configured to
-only execute code from trusted sites, and be careful which sites you trust. For
-example there is no point in having Privoxy modify the User-Agent header, if
-websites can get all the information they want through JavaScript, ActiveX,
-Flash, Java etc.
+Most of Privoxy's privacy-enhancing features can be easily subverted by an
+insecure browser configuration, therefore you should use a browser that can be
+configured to only execute code from trusted sites, and be careful which sites
+you trust. For example there is no point in having Privoxy modify the
+User-Agent header, if websites can get all the information they want through
+JavaScript, ActiveX, Flash, Java etc.
A few browsers disclose the user's email address in certain situations, such as
when transferring a file by FTP. Privoxy does not filter FTP. If you need this
4.10. How do I use Privoxy together with Tor?
-Before you configure Privoxy to use Tor (http://tor.eff.org/), please follow
-the User Manual chapters 2. Installation and 5. Startup to make sure Privoxy
-itself is setup correctly.
+Before you configure Privoxy to use Tor, please follow the User Manual chapters
+2. Installation and 5. Startup to make sure Privoxy itself is setup correctly.
If it is, refer to Tor's extensive documentation to learn how to install Tor,
and make sure Tor's logfile says that "Tor has successfully opened a circuit"
If you verified that Privoxy and Tor are working, it is time to connect them.
As far as Privoxy is concerned, Tor is just another proxy that can be reached
by socks4 or socks4a. Most likely you are interested in Tor to increase your
-anonymity level, therefore you should use socks4a, to make sure Privoxy's DNS
-requests are done through Tor and thus invisible to your local network.
+anonymity level, therefore you should use socks4a, to make sure DNS requests
+are done through Tor and thus invisible to your local network.
Since Privoxy 3.0.5, its main configuration file is already prepared for Tor,
if you are using a default Tor configuration and run it on the same system as
Privoxy, you just have to edit the forwarding section and uncomment the line:
-# forward-socks4a / 127.0.0.1:9050 .
-
+# forward-socks4a / 127.0.0.1:9050 .
+
+
+
+This is enough to reach the Internet, but additionally you might want to
+uncomment the following forward rules, to make sure your local network is still
+reachable through Privoxy:
+
+# forward 192.168.*.*/ .
+# forward 10.*.*.*/ .
+# forward 127.*.*.*/ .
-This is enough to reach the Internet, but additionally you should uncomment the
-following forward rules, to make sure your local network is still reachable
-through Privoxy:
-# forward 192.168.*.*/ .
-# forward 10.*.*.*/ .
-# forward 127.*.*.*/ .
-
Unencrypted connections to systems in these address ranges will be as (un)
-secure as the local network is, but the alternative is that you can't reach the
-network at all. If you also want to be able to reach servers in your local
-network by using their names, you will need additional exceptions that look
-like this:
+secure as the local network is, but the alternative is that your browser can't
+reach the network at all. Then again, that may actually be desired and if you
+don't know for sure that your browser has to be able to reach the local
+network, there's no reason to allow it.
+
+If you want your browser to be able to reach servers in your local network by
+using their names, you will need additional exceptions that look like this:
+
+# forward localhost/ .
+
-# forward localhost/ .
-
Save the modified configuration file and open http://config.privoxy.org/
show-status/ in your browser, confirm that Privoxy has reloaded its
Afterward, please take the time to at least skim through the rest of Tor's
documentation. Make sure you understand what Tor does, why it is no replacement
-for application level security, and why you shouldn't use it for unencrypted
-logins.
+for application level security, and why you probably don't want to use it for
+unencrypted logins.
-------------------------------------------------------------------------------
very different. There are many, many ways that this can be handled, so having
hard and fast rules, is tricky.
-"User-Agent" is often used in this way to identify the browser, and adjust
-content accordingly. Changing this now (at least not further than removing the
-OS information) is not recommended, since so many sites do look for it. You may
-get undesirable results by changing just this one aspect.
+The "User-Agent" is sometimes used in this way to identify the browser, and
+adjust content accordingly.
-Also, different browsers use different encodings of Russian and Czech
-characters, certain web servers convert pages on-the-fly according to the User
-Agent header. Giving a "User Agent" with the wrong operating system or browser
+Also, different browsers use different encodings of non-English characters,
+certain web servers convert pages on-the-fly according to the User Agent
+header. Giving a "User Agent" with the wrong operating system or browser
manufacturer causes some sites in these languages to be garbled; Surfers to
Eastern European sites should change it to something closer. And then some page
access counters work by looking at the "Referer" header; they may fail or break
if unavailable. The weather maps of Intellicast have been blocked by their
server when no "Referer" or cookie is provided, is another example. (But you
can forge both headers without giving information away). There are many other
-ways things that can go wrong when trying to fool a web server. The results of
-which could inadvertently cause pages to load incorrectly, partially, or even
-not at all. And there may be no obvious clues as to just what went wrong, or
-why. Nowhere will there be a message that says "Turn off fast-redirects or
-else! "
+ways things can go wrong when trying to fool a web server. The results of which
+could inadvertently cause pages to load incorrectly, partially, or even not at
+all. And there may be no obvious clues as to just what went wrong, or why.
+Nowhere will there be a message that says "Turn off fast-redirects or else! "
Similar thoughts apply to modifying JavaScript, and, to a lesser degree, HTML
elements.
4.12. Can Privoxy act as a "caching" proxy to speed up web browsing?
-No, it does not have this ability at all. You want something like Squid for
-this. And, yes, before you ask, Privoxy can co-exist with other kinds of
-proxies like Squid. See the forwarding chapter in the user manual for details.
+No, it does not have this ability at all. You want something like Squid or
+Polipo for this. And, yes, before you ask, Privoxy can co-exist with other
+kinds of proxies like Squid. See the forwarding chapter in the user manual for
+details.
-------------------------------------------------------------------------------
4.13. What about as a firewall? Can Privoxy protect me?
-Not in the way you mean, or in the way a true firewall can. Privoxy can help
-protect your privacy, but not protect you from intrusion attempts. It is, of
-course, perfectly possible and recommended to use both.
+Not in the way you mean, or in the way some firewall vendors claim they can.
+Privoxy can help protect your privacy, but can't protect your system from
+intrusion attempts. It is, of course, perfectly possible to use both.
-------------------------------------------------------------------------------
4.16. Privoxy runs as a "server". How secure is it? Do I need to take any
special precautions?
-There are no known exploits that might affect Privoxy. On Unix-like systems,
-Privoxy can run as a non-privileged user, which is how we recommend it be run.
-Also, by default Privoxy only listens to requests from "localhost" only. The
-server aspect of Privoxy is not itself directly exposed to the Internet in this
-configuration. If you want to have Privoxy serve as a LAN proxy, this will have
-to be opened up to allow for LAN requests. In this case, we'd recommend you
-specify only the LAN gateway address, e.g. 192.168.1.1, in the main Privoxy
+On Unix-like systems, Privoxy can run as a non-privileged user, which is how we
+recommend it be run. Also, by default Privoxy listens to requests from
+"localhost" only.
+
+The server aspect of Privoxy is not itself directly exposed to the Internet in
+this configuration. If you want to have Privoxy serve as a LAN proxy, this will
+have to be opened up to allow for LAN requests. In this case, we'd recommend
+you specify only the LAN gateway address, e.g. 192.168.1.1, in the main Privoxy
configuration file and check all access control and security options. All LAN
hosts can then use this as their proxy address in the browser proxy
configuration, but Privoxy will not listen on any external interfaces. ACLs can
-------------------------------------------------------------------------------
-4.17. How can I temporarily disable Privoxy?
+4.17. Can I temporarily disable Privoxy?
+
+Privoxy doesn't have a transparent proxy mode, but you can toggle off blocking
+and content filtering.
+
+The easiest way to do that is to point your browser to the remote toggle URL:
+http://config.privoxy.org/toggle.
-The easiest way is to access Privoxy with your browser by using the remote
-toggle URL: http://config.privoxy.org/toggle. See the Bookmarklets section of
-the User Manual for an easy way to access this feature.
+See the Bookmarklets section of the User Manual for an easy way to access this
+feature. Note that this is a feature that may need to be enabled in the main
+config file.
-------------------------------------------------------------------------------
4.18. When "disabled" is Privoxy totally out of the picture?
-No, this just means all filtering and actions are disabled. Privoxy is still
-acting as a proxy, but just not doing any of the things that Privoxy would
+No, this just means all optional filtering and actions are disabled. Privoxy is
+still acting as a proxy, but just doing less of the things that Privoxy would
normally be expected to do. It is still a "middle-man" in the interaction
between your browser and web sites. See below to bypass the proxy.
not go out to the 'net), and the familiar CGI configuration is returned to the
browser, and the log consequently will show a "crunch".
+Since version 3.0.7, Privoxy will also log the crunch reason. If you are using
+an older version you might want to upgrade.
+
-------------------------------------------------------------------------------
4.21. Can Privoxy effect files that I download from a webserver? FTP server?
"good" content that we do want. Privoxy is blind to the differences, and can
only distinguish "good from bad" by the configuration parameters we give it.
-Privoxy knows the differences in files according to the "Document Type" as
+Privoxy knows the differences in files according to the "Content Type" as
reported by the webserver. If this is reported accurately (e.g. "application/
zip" for a zip archive), then Privoxy knows to ignore these where appropriate.
Privoxy potentially can filter HTML as well as plain text documents, subject to
Note that versions later than 3.0.2 do NOT filter document types reported as
"text/plain". Prior to this, Privoxy did filter this document type.
-In short, filtering is "ON" if a) the Document Type as reported by the
-webserver is appropriate and b) the configuration allows it (or at least does
-not disallow it). That's it. There is no magic cookie anywhere to say this is
-"good" and this is "bad". It's the configuration that let's it all happen or
+In short, filtering is "ON" if a) the content type as reported by the webserver
+is appropriate and b) the configuration allows it (or at least does not
+disallow it). That's it. There is no magic cookie anywhere to say this is
+"good" and this is "bad". It's the configuration that lets it all happen or
not.
If you download text files, you probably do not want these to be filtered,
There is no reason to use this technique in conjunction with Privoxy. Privoxy
does essentially the same thing, much more elegantly and with much more
flexibility. A large HOSTS file, in fact, not only duplicates effort, but may
-get in the way. It is recommended to remove such entries from your HOSTS file.
-If you think your hosts list is neglected by Privoxy's configuration, consider
-adding your list to your user.action file:
+get in the way and seriously slow down your system. It is recommended to remove
+such entries from your HOSTS file. If you think your hosts list is neglected by
+Privoxy's configuration, consider adding your list to your user.action file:
+
+ { +block }
+ www.ad.example1.com
+ ad.example2.com
+ ads.galore.example.com
+ etc.example.com
- { +block }
- www.ad.example1.com
- ad.example2.com
- ads.galore.example.com
- etc.example.com
-------------------------------------------------------------------------------
http://www.privoxy.org/faq/, the Privoxy FAQ.
-http://sourceforge.net/projects/ijbswa/, the Project Page for Privoxy on
-SourceForge.
+http://sourceforge.net/projects/ijbswa/, the Project Page for Privoxy on
+SourceForge.
-http://config.privoxy.org/, the web-based user interface. Privoxy must be
-running for this to work. Shortcut: http://p.p/
+http://config.privoxy.org/, the web-based user interface. Privoxy must be
+running for this to work. Shortcut: http://p.p/
-http://sourceforge.net/tracker/?group_id=11118&atid=460288, to submit "misses"
-and other configuration related suggestions to the developers.
+http://sourceforge.net/tracker/?group_id=11118&atid=460288, to submit "misses"
+and other configuration related suggestions to the developers.
-http://www.junkbusters.com/ht/en/cookies.html, an explanation how cookies are
-used to track web users.
+http://www.junkbusters.com/ht/en/cookies.html, an explanation how cookies are
+used to track web users.
http://www.junkbusters.com/ijb.html, the original Internet Junkbuster.
-http://privacy.net/, a useful site to check what information about you is
-leaked while you browse the web.
+http://privacy.net/, a useful site to check what information about you is
+leaked while you browse the web.
+
+http://www.squid-cache.org/, a popular caching proxy, which is often used
+together with Privoxy.
-http://www.squid-cache.org/, a very popular caching proxy, which is often used
-together with Privoxy.
+http://www.pps.jussieu.fr/~jch/software/polipo/, Polipo is a caching proxy with
+advanced features like pipelining, multiplexing and caching of partial
+instances. In many setups it can be used as Squid replacement.
-http://tor.eff.org/, Tor can help anonymize web browsing, web publishing,
-instant messaging, IRC, SSH, and other applications.
+http://tor.eff.org/, Tor can help anonymize web browsing, web publishing,
+instant messaging, IRC, SSH, and other applications.
http://www.privoxy.org/developer-manual/, the Privoxy developer manual.
default configuration as shipped. You have either manually activated the "fun"
filter which is clearly labeled "Text replacements for subversive browsing fun!
" or you are using an older Privoxy version and have implicitly activated it by
-choosing the "Adventuresome" profile in the web-based editor. Please upgrade!
+choosing the "Adventuresome" profile in the web-based editor. Please upgrade.
+
+-------------------------------------------------------------------------------
+
+4.26. Does Privoxy produce "valid" HTML (or XHTML)?
+
+Privoxy generates HTML in both its own "templates", and possibly whenever there
+are text substitutions via a Privoxy filter. While this should always conform
+to the HTML 4.01 specifications, it has not been validated against this or any
+other standard.
-------------------------------------------------------------------------------
There are several possibilities:
* Privoxy is not running. Solution: verify that Privoxy is installed
- correctly, has not crashed, and is indeed running. Look at Privoxy's logs
- to see what they say.
-
+ correctly, has not crashed, and is indeed running. Turn on Privoxy's
+ logging, and look at the logs to see what they say.
+
* Or your browser is configured for a different port than what Privoxy is
using. Solution: verify that Privoxy and your browser are set to the same
port (listen-address).
-
+
* Or if using a forwarding rule, you have a configuration problem or a
problem with a host in the forwarding chain. Solution: temporarily alter
your configuration and take the forwarders out of the equation.
-
+
* Or you have a firewall that is interfering and blocking you. Solution: try
disabling or removing the firewall as a simple test.
-
+
-------------------------------------------------------------------------------
5.2. Why am I getting a 503 Error (WSAECONNREFUSED) on every page?
different from the site URL itself. Most ads are hosted on different servers
than the main site itself. If you right-click on the ad, you should be able to
get all the relevant information you need. Alternately, you can find the
-correct URL by looking at Privoxy's logs.
+correct URL by looking at Privoxy's logs (you may need to enable logging in the
+main config file if its disabled).
Below is a slightly modified real-life log snippet that originates with one
requested URL: www.example.com (name of site was changed for this example, the
making our job a little easier. Privoxy has "crunched" (meaning caught and
BLOCKED) quite a few items in this example, but perhaps missed a few as well.
-Request: www.example.com/
-Request: www.example.com/favicon.ico
-Request: img.example.com/main.css
-Request: img.example.com/sr.js
-Request: example.betamarker.com/example.html
-Request: www.lik-sang.com/Banners/bestsellers/skyscraper.php?likref=BSellers
-Request: img.example.com/pb.png
-Request: www.google-analytics.com/urchin.js crunch!
-Request: www.advertising-department.com/ats/switch.ps.php?26856 crunch!
-Request: img.example.com/p.gif
-Request: www.popuptraffic.com/assign.php?l=example&mode=behind crunch!
-Request: www.popuptraffic.com/scripts/popup.php?hid=5c3cf&tmpl=PBa.tmpl crunch!
-Request: www.popuptraffic.com/assign.php?l=example crunch!
-Request: www.lik-sang.com/Banners/best_sellers/best_sellers.css
-Request: www.adtrak.net/adx.js crunch!
-Request: img.example.com/hbg.gif
-Request: img.example.com/example.jpg
-Request: img.example.com/mt.png
-Request: img.example.com/mm.png
-Request: img.example.com/mb.png
-Request: www.popuptraffic.com/scripts/popup.php?hid=a71b91fa5&tmpl=Ua.tmp crunch!
-Request: www.example.com/tracker.js
-Request: www.lik-sang.com/Banners/best_sellers/lsi_head.gif
-Request: www.adtrak.net/adjs.php?n=020548130&what=zone:61 crunch!
-Request: www.adtrak.net/adjs.php?n=463594413&what=zone:58&source=Ua crunch!
-Request: www.lik-sang.com/Banners/best_sellers/bottomani.swf
-Request: mmm.elitemediagroup.net/install.php?allowpop=no&popupmincook=0&allowsp2=1 crunch!
-Request: www.example.com/tracker.js?screen=1400x1050&win=962x693
-Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=61 crunch!
-Request: 66.70.21.80/scripts/click.php?hid=5c3cf599a9efd0320d26&si
-Request: 66.70.21.80/img/pixel.gif
-Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=58&source=Ua&block=86400 crunch!
-Request: 66.70.21.80/scripts/click.php?hid=a71b9f6504b0c5681fa5&si=Ua
+Request: www.example.com/
+Request: www.example.com/favicon.ico
+Request: img.example.com/main.css
+Request: img.example.com/sr.js
+Request: example.betamarker.com/example.html
+Request: www.lik-sang.com/Banners/bestsellers/skyscraper.php?likref=BSellers
+Request: img.example.com/pb.png
+Request: www.google-analytics.com/urchin.js crunch! (Blocked)
+Request: www.advertising-department.com/ats/switch.ps.php?26856 crunch! (Blocked)
+Request: img.example.com/p.gif
+Request: www.popuptraffic.com/assign.php?l=example&mode=behind crunch! (Blocked)
+Request: www.popuptraffic.com/scripts/popup.php?hid=5c3cf&tmpl=PBa.tmpl crunch! (Blocked)
+Request: www.popuptraffic.com/assign.php?l=example crunch! (Blocked)
+Request: www.lik-sang.com/Banners/best_sellers/best_sellers.css
+Request: www.adtrak.net/adx.js crunch! (Blocked)
+Request: img.example.com/hbg.gif
+Request: img.example.com/example.jpg
+Request: img.example.com/mt.png
+Request: img.example.com/mm.png
+Request: img.example.com/mb.png
+Request: www.popuptraffic.com/scripts/popup.php?hid=a71b91fa5&tmpl=Ua.tmp crunch! (Blocked)
+Request: www.example.com/tracker.js
+Request: www.lik-sang.com/Banners/best_sellers/lsi_head.gif
+Request: www.adtrak.net/adjs.php?n=020548130&what=zone:61 crunch! (Blocked)
+Request: www.adtrak.net/adjs.php?n=463594413&what=zone:58&source=Ua crunch! (Blocked)
+Request: www.lik-sang.com/Banners/best_sellers/bottomani.swf
+Request: mmm.elitemediagroup.net/install.php?allowpop=no&popupmincook=0&allowsp2=1 crunch! (Blocked)
+Request: www.example.com/tracker.js?screen=1400x1050&win=962x693
+Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=61 crunch! (Blocked)
+Request: 66.70.21.80/scripts/click.php?hid=5c3cf599a9efd0320d26&si
+Request: 66.70.21.80/img/pixel.gif
+Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=58&source=Ua&block=86400 crunch! (Blocked)
+Request: 66.70.21.80/scripts/click.php?hid=a71b9f6504b0c5681fa5&si=Ua
+
Despite 12 out of 32 requests being blocked, the page looked, and seemed to
behave perfectly "normal" (minus some ads, of course).
5.4. One of my favorite sites does not work with Privoxy. What can I do?
First verify that it is indeed a Privoxy problem, by toggling off Privoxy
-through http://config.privoxy.org/toggle, and then shift-reloading the problem
-page (i.e. holding down the shift key while clicking reload. Alternatively,
-flush your browser's disk and memory caches).
+through http://config.privoxy.org/toggle (the toggle feature may need to be
+enabled in the main config), and then shift-reloading the problem page (i.e.
+holding down the shift key while clicking reload. Alternatively, flush your
+browser's disk and memory caches).
If the problem went away, we know we have a configuration related problem. Now
go to http://config.privoxy.org/show-url-info and paste the full URL of the
page in question into the prompt. See which actions are being applied to the
URL, and which matches in which actions files are responsible for that. It
might be helpful also to look at your logs for this site too, to see what else
-might be happening. Many sites are complex and require a number of related
-pages to help present their content. Look at what else might be used by the
-page in question, and what of that might be required. Now, armed with this
-information, go to http://config.privoxy.org/show-status and select the
-appropriate actions files for editing.
+might be happening (note: logging may need to be enabled in the main config
+file). Many sites are complex and require a number of related pages to help
+present their content. Look at what else might be used by the page in question,
+and what of that might be required. Now, armed with this information, go to
+http://config.privoxy.org/show-status and select the appropriate actions files
+for editing.
You can now either look for a section which disables the actions that you
suspect to cause the problem and add a pattern for your site there, or make up
To find out if this is in fact the source of the problem, try adding the site
to a -prevent-compression section in user.action:
- # Make exceptions for ill-behaved sites:
- #
- {-prevent-compression}
- .example.com
+ # Make exceptions for ill-behaved sites:
+ #
+ {-prevent-compression}
+ .example.com
+
If that works, you may also want to report the problem to the site's
webmasters, telling them to use zlib.output_compression instead of ob_gzhandler
5.13. Pages with UTF-8 fonts are garbled.
This is caused by the "demoronizer" filter. You should either upgrade Privoxy,
-or at least upgrade to the most recent default.action file available from
+or at least upgrade to the most recent default.action file available from
SourceForge. Or you can simply disable the demoronizer filter.
-------------------------------------------------------------------------------
5.14. Why are binary files (such as images) corrupted when Privoxy is used?
This may also be caused by the "demoronizer" filter, in conjunction with a web
-server that is misreporting a file type. Binary files are exempted from
+server that is misreporting the content type. Binary files are exempted from
Privoxy's filtering (unless the web server by mistake says the file is
something else). Either upgrade Privoxy, or go to the most recent
default.action file available from SourceForge.
corruption of the fonts, and thus should not be on.
On the other hand, if you use non-Microsoft products, and you occasionally
-notice wierd characters on pages, you might want to try it.
+notice weird characters on pages, you might want to try it.
-------------------------------------------------------------------------------
outcome was. And tries to give a coherent message if there seems to be a
problem. In some cases, this might otherwise be mitigated by the browser itself
which might try some work-arounds and alternate approaches (e.g adding "www."
-to the URL). In other cases, if Privoxy is being chained with another proxy,
-this could complicate the issue, and cause undue delays and timeouts. In the
-case of a "socks4a" proxy, the socks server handles all the DNS. Privoxy would
-just be the "messenger" which is reporting whatever problem occurred
-downstream, and not the root cause of the error.
+to the URL).
-In any case, newer versions include various improvements to help Privoxy better
-handle these cases.
+In other cases, if Privoxy is being chained with another proxy, this could
+complicate the issue, and cause undue delays and timeouts. In the case of a
+"socks4a" proxy, the socks server handles all the DNS. Privoxy would just be
+the "messenger" which is reporting whatever problem occurred downstream, and
+not the root cause of the error.
+
+In any case, versions newer than 3.0.3 include various improvements to help
+Privoxy better handle these cases.
-------------------------------------------------------------------------------
It's probably due to compression. It is a common practice for web servers to
send their content "compressed" in order to speed things up, and then let the
-browser "uncompress" them. Privoxy does not (yet) support compression. But we
-can force the web server to bend to our will ;-) So for filtering, make sure
-you have prevent-compression turned ON!
+browser "uncompress" them. When compiled with zlib support Privoxy can
+decompress content before filtering, otherwise you may want to enable
+prevent-compression.
-------------------------------------------------------------------------------
6.1. Get Support
-For casual users, our support forum at SourceForge is probably best suited:
+For casual users, our support forum at SourceForge is probably best suited:
http://sourceforge.net/tracker/?group_id=11118&atid=211118
All users are of course welcome to discuss their issues on the users mailing
list, where the developers also hang around.
+Note that the Privoxy mailing lists are moderated. Posts from unsubscribed
+addresses have to be accepted manually by a moderator. This may cause a delay
+of several days and if you use a subject that doesn't clearly mention Privoxy
+or one of its features, your message may be accidentally discarded as spam.
+
+If you aren't subscribed, you should therefore spend a few seconds to come up
+with a proper subject. Additionally you should make it clear that you want to
+get CC'd. Otherwise some responses will be directed to the mailing list only,
+and you won't see them.
+
-------------------------------------------------------------------------------
6.2. Reporting Problems
* Configuration issues, such as ads that slip through, or sites that don't
function properly due to one Privoxy "action" or another being turned "on".
-
+
* "Bugs" in the programming code that makes up Privoxy, such as that might
cause a crash.
-
+
-------------------------------------------------------------------------------
6.2.1. Reporting Ads or Other Configuration Problems
6.2.2. Reporting Bugs
-Please report all bugs only through our bug tracker: http://sourceforge.net/
-tracker/?group_id=11118&atid=111118.
+Please report all bugs through our bug tracker: http://sourceforge.net/tracker
+/?group_id=11118&atid=111118.
Before doing so, please make sure that the bug has not already been submitted
and observe the additional hints at the top of the submit form. If already
submitted, please feel free to add any info to the original report that might
help to solve the issue.
-Please try to verify that it is a Privoxy bug, and not a browser or site bug
-first. If unsure, try toggling off Privoxy, and see if the problem persists. If
-you are using your own custom configuration, please try the stock configs to
-see if the problem is configuration related.
+Please try to verify that it is a Privoxy bug, and not a browser or site bug or
+documented behaviour that just happens to be different than what you expected.
+If unsure, try toggling off Privoxy, and see if the problem persists.
-If not using the latest version, the bug may have been found and fixed in the
-meantime. We would appreciate if you could take the time to upgrade to the
-latest version (or even the latest CVS snapshot) and verify your bug.
+If you are using your own custom configuration, please try the stock configs to
+see if the problem is configuration related. If you're having problems with a
+feature that is disabled by default, please ask around on the mailing list if
+others can reproduce the problem.
+
+If you aren't using the latest Privoxy version, the bug may have been found and
+fixed in the meantime. We would appreciate if you could take the time to
+upgrade to the latest version (or even the latest CVS snapshot) and verify that
+your bug still exists.
Please be sure to provide the following information:
- * The exact Privoxy version of the proxy software (if you got the source from
- CVS, please also provide the source code revisions as shown in http://
+ * The exact Privoxy version you are using (if you got the source from CVS,
+ please also provide the source code revisions as shown in http://
config.privoxy.org/show-version).
-
+
* The operating system and versions you run Privoxy on, (e.g. Windows XP
SP2), if you are using a Unix flavor, sending the output of "uname -a"
- should do.
-
+ should do, in case of GNU/Linux, please also name the distribution.
+
* The name, platform, and version of the browser you were using (e.g.
Internet Explorer v5.5 for Mac).
-
+
* The URL where the problem occurred, or some way for us to duplicate the
problem (e.g. http://somesite.example.com/?somethingelse=123).
-
- * Whether your version of Privoxy is one supplied by the developers of
- Privoxy via SourceForge, or somewhere else.
-
+
+ * Whether your version of Privoxy is one supplied by the Privoxy developers
+ via SourceForge, or if you got your copy somewhere else.
+
* Whether you are using Privoxy in tandem with another proxy such as Tor. If
- so, please try disabling the other proxy.
-
+ so, please temporary disable the other proxy to see if the symptoms change.
+
* Whether you are using a personal firewall product. If so, does Privoxy work
without it?
-
+
* Any other pertinent information to help identify the problem such as config
or log file excerpts (yes, you should have log file entries for each action
taken).
-
- * Please provide your SF login, or email address, in case we need to contact
- you.
-
+
+You don't have to tell us your actual name when filing a problem report, but
+please use a nickname so we can differentiate between your messages and the
+ones entered by other "anonymous" users that may respond to your request if
+they have the same problem or already found a solution.
+
+Please also check the status of your request a few days after submitting it, as
+we may request additional information. If you use a SF id, you should
+automatically get a mail when someone responds to your request.
+
The appendix of the Privoxy User Manual also has helpful information on
understanding actions, and action debugging.
7. Privoxy Copyright, License and History
-Copyright © 2001 - 2006 by Privoxy Developers <
+Copyright 2001-2007 by Privoxy Developers <
ijbswa-developers@lists.sourceforge.net>
-Some source code is based on code Copyright © 1997 by Anonymous Coders and
+Some source code is based on code Copyright 1997 by Anonymous Coders and
Junkbusters, Inc. and licensed under the GNU General Public License.
Portions of this document are "borrowed" from the original Junkbuster (tm) FAQ,
7.2. History
-A long time ago, there was the Internet Junkbuster, by Anonymous Coders and
+A long time ago, there was the Internet Junkbuster, by Anonymous Coders and
Junkbusters Corporation. This saved many users a lot of pain in the early days
of web advertising and user tracking.
projects / privoxy.git / blobdiff