Junkbuster Frequently Asked Questions

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-Junkbuster Frequently Asked Questions +Privoxy Frequently Asked Questions + + + + + + Copyright &my-copy; 2001-2006 by + Privoxy Developers + + + +$Id: faq.sgml,v 2.18 2006/09/22 01:27:55 hal9 Exp $ -$Id: faq.sgml,v 1.5 2002/03/02 15:50:04 swa Exp $ + + + + + This is here to keep vim syntax file from breaking :/ + If I knew enough to fix it, I would. + PLEASE DO NOT REMOVE! HB: hal@foobox.net + + +]]> - The FAQ document gives users and developers alike answers to frequently -asked questions about the Internet Junkbuster. The Internet Junkbuster is an application -that provides privacy and security to the user of the world wide web. - - -You can find the latest version of the document at http://ijbswa.sourceforge.net/faq/. -Please see the Contact section in the user-manual if you want to contact the developers. + This FAQ gives quick answers to frequently asked questions about + Privoxy. + It is not a substitute for the + Privoxy User Manual. + + + What is Privoxy? &p-intro; + + - Feel free to send a note to the developers at ijbswa-developers@lists.sourceforge.net. + Please note that this document is a work in progress. This copy represents + the state at the release of version &p-version;. + 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. + + + + - -Introduction - - Fillme. - - - - - -Frequently Asked Questions - -Installation +General Information +Who should use Privoxy? - Fillme. + Anyone that is interested in security, privacy, or in + finer-grained control over their web and Internet experience. + Everyone is encouraged to try &my-app;. - - -Configuration - -How can I make my Yahoo account work? +Is Privoxy the best choice for +me? - Fillme. + &my-app; 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 &my-app;. - - - How can I make my Hotmail account work? - - Fillme. + + 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. - + - How can I make my GMX account work? +What is a <quote>proxy</quote>? How does +Privoxy work? - Fillme. + A web proxy + is a service, based on a software such as + Privoxy, that clients (i.e. browsers) can use + instead of connecting directly to web servers on the Internet. The + clients then ask the proxy to fetch the objects they need (web pages, + images, movies etc) on their behalf, and when the proxy has done so, it + hands the results back to the client. It is a go-between. See + the Wikipedia proxy + definition for more. - - - Why can I change the configuration with a -browser? Does that not raise security issues? -What I don't understand, is how I can browser edit the config file as a -regular user, while the whole /etc/junkbuster hierarchy belongs to the user -"junkbuster", with only 644 perms. + There are many reasons to use web proxies, such as security (firewalling), + efficiency (caching) and others, and there are any number of proxies + to accommodate those needs. + + + Privoxy is a proxy that is primarily focused on privacy + protection, ad and junk elimination and freeing the user from restrictions placed on his + activities. Sitting between your browser(s) and the Internet, + it is in a perfect position to filter outbound personal information that your + browser is leaking, as well as inbound junk. It uses a variety of techniques to do + this, all of which are under your complete control via the various configuration + files and options. + + -When you use the browser-based editor, JunkBuster itself is writing to the -config files. Because JunkBuster is running as the user "junkbuster", it can -update the config files. +What is this new version of +<quote><citetitle>Junkbuster</citetitle></quote>? -If you don't like this, setting "enable-edit-actions 0" in the config file -will disable the browser-based editor. If you're that paranoid, you should -also consider setting "enable-remote-toggle 0" to prevent browser-based -enabling/disabling of JunkBuster. + + &history; + + + -Note that normally only local users can connect to JunkBuster, so this is not -(normally) a security problem. - - + +Why <quote>Privoxy</quote>? Why change the name from +Junkbuster at all? + + Junkbusters Corporation + continues to offer their original version of the Internet + Junkbuster, so publishing our + Junkbuster-derived software under the same name + led to confusion. + + + There are also potential legal complications from the continued use of the + Junkbuster name, which is a registered trademark of + Junkbusters Corporation. + There are, however, no objections from Junkbusters Corporation to the + Privoxy project itself, and they, in fact, still + share our ideals and goals. + + + The developers also believed that there are so many improvements over the original + code, that it was time to make a clean break from the past and make + a name in their own right. + + + Privoxy is the + Privacy Enhancing Proxy. Also, its content + modification and junk suppression gives you, the user, more + control, more freedom, and allows you to browse your personal and + private edition of the web. + - -Misc +How does Privoxy differ +from the old Junkbuster? + + 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. What's New + page for the latest updates.]]> + + + Privoxy's new features include: + + + + &newfeatures; + -I noticed considerable -delays in page requests compared to the old IJB. What's wrong? + + + +How does Privoxy know what is +an ad, and what is not? + + Privoxy's approach to blocking ads is twofold: + -Using the default filtering configuration, I noticed considerable delays in -page requests compared to the old IJB. Loading pages with large contents -seemed to take forever, then suddenly delivering all the content at once. + First, there are certain patterns in the locations (URLs) + of banner images. This applies to both the path (you wouldn't guess how many + web sites serve their banners from a directory called banners!) + and the host (blocking the big banner hosting services like doublecklick.net + already helps a lot). Privoxy takes advantage of this + fact by using URL + patterns to sort out and block the requests for things that sound + like they would be ads or banners. + + + Second, banners tend to come in certain sizes. But you + can't tell the size of an image by its URL without downloading it, and if you + do, it's too late to save bandwidth. Therefore, Privoxy + also inspects the HTML sources of web pages while they are loaded, and replaces + references to images with standard banner sizes by dummy references, so that + your browser doesn't request them anymore in the first place. + + + Both of this involves a certain amount of guesswork and is, of course, freely + and readily configurable. + + -The whole content must be loaded in order to filter, and nothing is is -sent to the browser during this time. The loading time does not really -change in real numbers, but the feeling is different, because most -browsers are able to start rendering incomplete content, giving the -user a feeling of "it works". + +Can Privoxy make mistakes? +This does not sound very scientific. + + Actually, it's a black art ;-) And yes, it is always possible to have a broad + rule accidentally block or change something by mistake. You will almost surely + run into such situations at some point. It is tricky writing rules to + cover every conceivable possibility, and not occasionally get false positives. + -To modify the content of a page (i.e. make frames resizeable again, etc.) and -not just replace ads, the Internet Junkbuster needs to download the entire -page first, do its content magic and then send the page to the browser. + + But this should not be a big concern since the + Privoxy configuration is very flexible, and + includes tools to help identify these types of situations so they can be + addressed as needed, allowing you to customize your installation. + (See the Troubleshooting section below.) - + + -What is the "http://i.j.b/"? + +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 unwanted content. + + + But 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! + -Since JunkBuster sits between your web browser and the Internet, it can be -programmed to handle certain pages specially. + You will have to tell your browser about Privoxy + (see the Installation section below). + + + + +My browser does the same things as +Privoxy. Why should I use +Privoxy at 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. + + + In addition, a proxy is good choice if you use multiple browsers, or + have a LAN with multiple computers. This way all the configuration + is in one place, and you don't have to maintain a similar configuration + for possibly many browsers. + + -With recent versions of JunkBuster (version 2.9.x), you can get some -information about JunkBuster and change some settings by going to -http://i.j.b/ or, equivalently, http://ijbswa.sourceforge.net/config/ -(Note that i.j.b is far easier to type but may not work in some -configurations). +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 &my-app; ourselves. + + -These pages are *not* forwarded to a server on the internet - instead they are -handled by a special web server which is built in to JunkBuster. +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. + + + 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! + -If you are not running JunkBuster, then http://i.j.b/ will fail, and -http://ijbswa.sourceforge.net/config/ will return a web page telling you -you're not running JunkBuster. + -If you have version 2.0.2, then the equivalent is -http://example.com/show-proxy-args (but you get far less information, and you -should really consider upgrading to 2.9.x). + +Can Privoxy remove spyware? Adware? Viruses? + + No. &my-app; cannot remove anything. It is not a removal tool. It is a + preventative. &my-app; can help prevent contact from sites + that use such tactics with approriate configuration rules, and thus could + conceivably prevent contamination from such sites. - + -I get the message 'Bad File Descriptor', why? + +Can I use Privoxy with other ad-blocking software? - Fillme. + &my-app; should work fine with other proxies and other software in general. - + + But it is probably not necessary to use &my-app; 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 its configuration to your liking. + + -How do I chain Junkbuster with other proxies -(e.g. squid)? +I would like to help you, what can I do? + +Would you like to participate? + + Well, we always need help. There is something for + everybody who wants to help us. We welcome new developers, packagers, + testers, documentation writers or really anyone with a desire to help in + any way. You DO NOT need to be a + programmer. There are many other tasks available. In fact, + the programmers often can't spend as much time programming because of some + of the other, more 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 developers + mailing list. Then, please read the Developer's Manual, at least + the pertinent sections. + - Fillme. + Once we have added you to the team, you'll have access to the CVS repository, and + together we'll find a suitable task for you. -I would like to help you, what do I do? +Contribute! - Well, helping the team is always a good idea. We welcome new developers, - RPM gurus or documentation makers. Simply get an account on sourceforge.net - and mail your id to the developer mailing list. Once we have added you to - the team, you'll have write access to the CVS repository, and we'll find a - suitable task for you together. + 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. -Do you still maintain the blocklists? +Software - No. The format of the blocklists has changed significantly in the versions - 2.9.x. Once we have released the new version, there will again be - blocklists that you can update automatically. + If you are a vendor of a web-related software like a browser, web server + or proxy, and would like us to ensure that Privoxy + runs smoothly with your product, you might consider supplying us with a + copy or license. We can't, however, guarantee that we will fix all potential + compatibility issues as a result. -How can I submit new ads? + + + + + + + + +Installation + + +Which browsers are supported by Privoxy? - As of now, please discontinue to submit new ad blocking infos. Once we - have released the new version, there will again be a form on the website, - which you can use to contribute new ads. + 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. - + -How can I hide my IP address? + +Which operating systems are supported? + +&supported; + + + +Can I use Privoxy with my email client? - You cannot hide your IP address with Junkbuster. + As long as there is some way to set a HTTP proxy for the client, then yes, + any application can be used, whether it is strictly speaking a + browser or not. Though this may not be the best approach for + dealing with some of the common abuses of HTML in email. See How can I configure Privoxy + with Outlook Express? below for more on + this. - + + Be aware that HTML email presents a number of unique security and privacy + related issues, that can require advanced skills to overcome. The developers + recommend using email clients that can be configured to convert HTML to plain + text for these reasons. + + + +Can I install + Privoxy over Junkbuster? + + 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! + + + + + +I just installed Privoxy. Is there anything +special I have to do now? -What is the imagefile (simage.ini, etc.) for? - Anytime the Junkbuster determines (with the help of the blocklist) that a URL - contains an advertisement, it has to decide whether this advertisement is an - image or not. The Junkbuster uses the imagefile for that purpose. + All browsers must 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 below. + You should also flush your browser's memory and disk cache to get rid of any + cached junk items, and remove any stored + cookies. + - - - -Contact the developers -Please see the user manual for information on how to contact the developers. +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). + + + 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 Secure (HTTPS) and + then the number 8118 for port. + This tells your browser to send all web requests to Privoxy + instead of directly to the Internet. + + + Privoxy can also be used to proxy for + a Local Area Network. In this case, your would enter either the IP + address of the LAN host where Privoxy + is running, or the equivalent hostname. Port assignment would be + same as 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. + + + + +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 like it. See above. You might also try flushing + the browser's caches to force a full re-reading of pages. You can verify + that Privoxy is running, and your browser + is correctly configured by entering the special URL: + http://p.p/. + + This should take you to a page titled This is Privoxy.. with + access to Privoxy's internal configuration. + If you see this, then you are good to go. If you receive a page saying + Privoxy is not running, then the browser is not set up to use + your Privoxy installation. + If you receive anything else (probably nothing at all), it could either + be that the browser is not set up correctly, or that + Privoxy is not running at all. Check the log file. For instructions + on starting Privoxy and browser configuration, + see the chapter + on starting Privoxy in the + User Manual. - - -Copyright and History -Please see the user manual for information on Copyright and History. + + + +I get a <quote>Privoxy is not being used</quote> dummy page although +Privoxy is running and being used. + + + 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. - - -See also -Please see the user manual for information on references. + + Now if http://p.p/ works for you, but + other parts of Privoxy's web interface show + the dummy page, your browser has cached a redirection it encountered before + Privoxy was being used. You need to clear your + browser's cache. Note that shift-reloading the dummy page won't help, since + that'll only refresh the dummy page, not the redirection that lead you there. + + + + 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. + + + - - + +Configuration + +Where can I get updated Actions Files? + + Based on your feedback and the continuing development, updates of + default.action will be + made available from time to time on the files section of + our project page. + + + + If you wish to receive an email notification whenever we release updates of + Privoxy or the actions file, subscribe + to our announce mailing list, ijbswa-announce@lists.sourceforge.net. + + + + +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. + 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. + ]]> + + + +What exactly is an <quote>actions</quote> file? + + + Actions files + are where various actions + that Privoxy could take while processing a certain + request, are configured. Typically, you would define a set of default actions + that apply to all URLs, then add exceptions to these defaults where needed. + There is a wide array of actions available that give the user a high degree + of control and flexibility on how to process each and every web page. + - This program is free software; you can redistribute it - and/or modify it under the terms of the GNU General - Public License as published by the Free Software - Foundation; either version 2 of the License, or (at - your option) any later version. + + 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 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. + - This program is distributed in the hope that it will - be useful, but WITHOUT ANY WARRANTY; without even the - implied warranty of MERCHANTABILITY or FITNESS FOR A - PARTICULAR PURPOSE. See the GNU General Public - License for more details. + - The GNU General Public License should be included with - this file. If not, you can view it at - http://www.gnu.org/copyleft/gpl.html - or write to the Free Software Foundation, Inc., 59 - Temple Place - Suite 330, Boston, MA 02111-1307, USA. + +The <quote>actions</quote> concept confuses me. Please list +some of these <quote>actions</quote>. + + 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. + + + + + +How are actions files configured? What is the easiest +way to do this? + + + 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. + + + + + +There are several different <quote>actions</quote> files. What are +the differences? + + As of Privoxy v2.9.15, three actions files + are being included, to be used for + different purposes: These are + default.action, the main actions file + which is actively maintained by the Privoxy + developers, user.action, where users are encouraged + to make their private customizations, and standard.action, + which is for internal Privoxy use only. + Please see the actions chapter + in the User Manual for a more + detailed explanation. + + + + Earlier versions included three different versions of the + default.action file. The new scheme allows for + greater flexibility of local configuration, and for browser based + selection of pre-defined aggressiveness levels. + + + + +How can I make my Yahoo/Hotmail/Gmail account work? + + The default configuration shouldn't impact the usability of any of these services. + It will, however, make all cookies + temporary, so that your browser will forget your + login credentials in between browser sessions. If you would like not to have to log + in manually each time you access those websites, simply 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 + + + 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 } + mail.google.com + + + Be sure to flush your browser's caches whenever making these kinds of + changes, just to make sure the changes take. + + + Make sure the domain, host and path are appropriate as well. Your browser can + tell you where you are specifically and you should use that information for + your configuration settings. Note that above it is not referenced as + gmail.com, which is a valid domain name. + + + + + What's the difference between the +<quote>Cautious</quote>, <quote>Medium</quote> and <quote>Advanced</quote> defaults? + + Configuring Privoxy is not entirely trivial. To + help you get started, we provide you with three different default action + profiles in the web based actions file editor at http://config.privoxy.org/show-status. + See the User + Manual for a list of actions, and how the default + profiles are set. + + + + Where the defaults are likely to break some sites, exceptions for + known popular problem sites are included, but in + general, the more aggressive your default settings are, the more exceptions + you will have to make later. See the User Manual + for a more detailed discussion. + + + + It should be noted that the Advanced profile (formerly known + as the Adventuresome profile) is more + aggressive, and will make use of some of + Privoxy's advanced features. Use at your own risk! + + + + + Why can I change the configuration +with a browser? Does that not raise security issues? + + It may seem strange that regular users can edit the config files with their + browsers, although the whole /etc/privoxy hierarchy + belongs to the user 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 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. + + + 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. + + + + + +What is the <filename>default.filter</filename> file? What is a <quote>filter</quote>? + + 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. + + + + 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 potentially a very powerful feature, but + requires some expertise in both regular expressions and HTML/HTTP. + user.filter, so they won't + be overwritten during upgrades. + The ability to define multiple filter files + in config is a new feature as of v. 3.0.5.]]> + + + + 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. + + + + + +How can I set up Privoxy to act as a proxy for my + LAN? + + By default, Privoxy only responds to requests + from 127.0.0.1 (localhost). To have it act as a server for + a network, this needs to be changed in the main configuration file. Look for + the listen-address + option, which may be commented out with a # symbol. Make sure + it is uncommented, and assign it the address of the LAN gateway interface, + and port number to use. Assuming your LAN address 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 + + + + 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 + + + + And then use Privoxy's + permit-access + feature to limit connections. A firewall in this situation is recommended + as well. + + + + The above steps should be the same for any TCP network, regardless of + operating system. + + + + If you run Privoxy on a LAN with untrusted users, + we recommend that you double-check the access control and security + options! + + + + + + +Instead of ads, now I get a checkerboard pattern. I don't want to see anything. + + The replacement for blocked images can be controlled with the set-image-blocker + action. You have the choice of a checkerboard pattern, a transparent 1x1 GIF + image (aka blank), or a redirect to a custom image of your choice. + Note that this choice only has effect for images which are blocked as images, i.e. + whose 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 + default.action file, or trough the web-based actions file editor. + + + + + +Why would anybody want to see a checkerboard pattern? + + Remember that telling which image is an ad and which + isn't, is mostly guesswork. While we hope that the standard configuration + is rather smart, it can and will make errors. The checkerboard image is visually + decent, but it shows you that and where images were blocked, which can be very + helpful in case some navigation aid or otherwise innocent image was + erroneously blocked. Some people might also enjoy seeing how many banners + they don't have to see.. + + + + + +I see some images being replaced by a 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 itself, but in separate HTML (sub)documents that are loaded into (i)frames + or (i)layers, and these external HTML documents are blocked. Being non-images + they get replaced by a substitute HTML page rather than a substitute image, + which wouldn't work out technically, since the browser expects and accepts + only HTML when it has requested an HTML document. + + + The substitute page adapts to the available space and shows itself as a + miniature two-liner if loaded into small frames, or full-blown with a + large red "BLOCKED" banner if space allows. + + + If you prefer the banners to be blocked by images, you must see to it that + the HTML documents in which they are embedded are not blocked. Clicking + the See why link offered in the substitute page will show + you which rule blocked the page. After changing the rule and un-blocking + the HTML documents, the browser will try to load the actual banner images + and the usual image blocking will (hopefully!) kick in. + + + + + +Can Privoxy run as a service +on Win2K/NT/XP? + +Windows service + functionality. See + the User Manual for details on how to install and configure + Privoxy as a service. + + + Earlier ]]>3.x versions could run as a system service using srvany.exe. + See the discussion at http://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118, + for details, and a sample configuration. + + + + + +How can I make Privoxy work with other +proxies like Squid or Tor? + + This can be done and is often useful to combine the benefits of + Privoxy with those of a another proxy. + See the forwarding chapter + in the User Manual which + describes how to do this, and the + How do I use Privoxy together with + Tor section below. + + + + +Can I just set Privoxy to use port 80 +and thus avoid individual browser configuration? + + + No, its more complicated than that. This only works with special kinds + of proxies known as transparent proxies (see below). + + + + + +Can Privoxy run as a <quote>transparent +</quote> 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. + + + + 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 recommend Transproxy + (http://transproxy.sourceforge.net/). + + + + + +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 have Privoxy configured to work + with IE, this configuration should automatically be shared. + + + + +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 pages and HTML mail. + Privoxy just blindly proxies all requests. In the + case of Outlook Express (see above), OE uses + IE anyway, and there is no way for Privoxy to ever + be able to distinguish between them (nor could any other proxy type application for + that matter). + + + For a good discussion of some of the issues involved (including privacy and + security issues), see + http://sourceforge.net/tracker/?func=detail&atid=211118&aid=629518&group_id=11118. + + + + +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 the &my-app; concept of + session-cookies-only. + There is also the possibility of using + Javascript to + set cookies (&my-app; calls these content-cookies). This + is trickier because the syntax can vary widely, and thus requires a certain + amount of guesswork. It is not realistic to catch all of these short of + disabling Javascript, which would break many sites. And lastly, if the + cookies are embedded in a HTTPS/SSL secure session via Javascript, they are beyond + Privoxy's reach. + + + All in all, &my-app; can help manage cookies in general, can help minimize + the loss of privacy posed by cookies, but can't realistically stop all + cookies. + + + + +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 + sessions. Sometimes there is a good reason for this, and the user's life is a + bit easier as a result. But there is a long history of some websites taking + 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 really need to be there. + + + See the + Wikipedia cookie + definition for more. + + + + +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. + + + 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 + + + Place the above in user.action. Note 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. + + + + +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 of Privoxy, each with + a unique listen-address and configuration path, and then + each of these can have their own configurations. Think of it as per-port + configuration. + + + Simple enough for a few users, but for large installations, consider having + groups of users that might share like configurations. + + + + +Can I set-up Privoxy as a whitelist of +<quote>good</quote> sites? + + Sure. There are a couple of things you can do for simple whitelisting. + Here's one real easy one: + + + ############################################################ + # Blacklist + ############################################################ + { +block } + / # Block *all* URLs + + ############################################################ + # Whitelist + ############################################################ + { -block } + kids.example.com + toys.example.com + games.example.com + + This allows access to only those three sites. + + + A more interesting approach is Privoxy's + trustfile concept, which incorporates the notion of + trusted referrers. See the User Manual Trust + documentation. + + + These are fairly simple approaches and are not completely foolproof. There + are various other configuration options that should be disabled (described + elsewhere here and in the User Manual) + so that users can't modify their own configuration and easily circumvent the + whitelist. + + + + + + + + + + +Miscellaneous + + +How much does Privoxy slow my browsing down? This +has to add extra time to browsing. + + How much of an impact depends on many things, including the CPU of the host + system, how aggressive the configuration is, which specific actions are being triggered, + the size of the page, etc. + + + Overall, it should not slow you down any in real terms, and may actually help + speed things up since ads, banners and other junk are not typically being + 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). + + + + 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, there may be + some 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. + + + + + +I notice considerable +delays in page requests compared to the old Junkbuster. 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 order for the filtering + mechanism to work, and nothing is sent to the browser during this time. + + + The loading time typically does not really change much in real numbers, but + the feeling is different, because most browsers are able to start rendering + incomplete content, giving the user a feeling of "it works". This effect is + more noticeable on slower dialup connections. Extremely large documents + may have some impact on the time to load the page where there is filtering + being done. But overall, the difference should be very minimal. If there is a + big impact, then probably some other problem is contributing. + + + Filtering is automatically disabled for inappropriate MIME types. But note + that 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. + + + + +What are "http://config.privoxy.org/" and +"http://p.p/"? + + http://config.privoxy.org/ is the + address of Privoxy's built-in user interface, and + http://p.p/ is a shortcut for it. + + + Since Privoxy sits between your web browser and the Internet, + it can simply intercept requests for these addresses and answer them with its built-in + web server. + + + This also makes for a good test for your browser configuration: If entering the + URL http://config.privoxy.org/ + takes you to a page saying This is Privoxy ..., everything is OK. + If you get a page saying Privoxy is not working instead, then + your browser didn't use Privoxy for the request, + hence it could 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 &p-version;. + + + + +How can I submit new ads, or report +problems? + +Please see the Contact section for +various ways to interact with the developers. + + + + +Why doesn't anyone answer my support +request? + +Rest assured that it has been read and considered. Why it is not answered, +could be for various reasons, including no one has a good answer for it, no +one has had time to yet investigate it thoroughly, it has been reported +numerous times already, or because not enough information was provided to help +us help you. Your efforts are not wasted, and we do appreciate them. + + + + + +How can I hide my IP address? + + If you run both the browser and the proxy locally, you cannot hide your IP + address with Privoxy or ultimately any other + software. The server needs to know your IP address so that it knows where to + send the responses back. + + + 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 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. + + + + + +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. + + + 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 it neither + hides your ip address, nor can it guarantee that the rest of the system + behaves correctly. There are several possibilities how a web sites can 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. + + + 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 feature, or are concerned about the + mail handler of your browser disclosing your email address, you might + consider products such as NSClean. + + + Browsers available only as binaries could use non-standard headers to give + out any information they can have access to: see the manufacturer's license + agreement. It's impossible to anticipate and prevent every breach of privacy + that might occur. The professionally paranoid prefer browsers available as + source code, because anticipating their behavior is easier. Trust the source, + Luke! + + + + + +A test site says I am not using a Proxy. + + Good! Actually, they are probably testing for some other kinds of proxies. + Hiding yourself completely would require additional steps. + + + +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. + + + 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 and it + looks like client functionality is working. + + + If either Tor or Privoxy + isn't working, their combination most likely will neither. Testing them on their + own will also help you to direct problem reports to the right audience. + If Privoxy isn't working, don't bother the + Tor developers. If Tor + isn't working, don't send bug reports to the Privoxy Team. + + + 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. + + + + Since Privoxy 3.0.5, its configuration (section 5.2) + is already prepared for Tor, if you are using a + default Tor configuration and run it on the same + system as &my-app;, you just have to uncomment the line: + + + +# forward-socks4a / 127.0.0.1:9050 . + + + + 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: + + + +# forward localhost/ . + + + + Save the modified configuration file and open + http://config.privoxy.org/show-status/ + in your browser, confirm that Privoxy has reloaded its configuration + and that there are no other forward lines, unless you know that you need them. I everything looks good, + refer to + Tor + Faq 4.2 to learn how to verify that you are really using Tor. + + + 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. + ]]> + + + +Might some things break because header information or +content is being altered? + + + Definitely. More and more sites use HTTP header content to decide what to + display and how to display it. There is many ways that this can be handled, + so having hard and fast rules, is tricky. + + + + User-Agent in particular 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 this. + + + + For instance, 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 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 can go wrong when trying to fool a web server. + + + + Similar thoughts apply to modifying JavaScript, and, to a lesser degree, + HTML elements. + + + + If you have problems with a site, you will have to adjust your configuration + accordingly. Cookies are probably the most likely adjustment that may + be required, but by no means the only one. + + + + + + +Can Privoxy act as a <quote>caching</quote> 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. + + + + +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. + + + + +I have large empty spaces / a checkerboard pattern now where +ads used to be. Why? + + It would be technically possible eliminate the banners in a way that frees + their screen estate in many cases, by doing all banner blocking with filters, + i.e. eliminating the whole image references from the HTML pages instead + of letting them stay in, and blocking the resulting requests for the + banners themselves. + + + But this would consume considerable CPU resources, would likely destroy + the layout of many web pages which rely on the banners consuming a certain + amount of screen space, and would fail in other cases, where the screen space + is reserved e.g. by tables anyway. Also, making the banners disappear without + a visual trace complicates troubleshooting. + + + So we won't support this in the default configuration, but you can of course + define appropriate filters yourself. + + + + +How can Privoxy filter Secure (HTTPS) URLs? + + Since secure HTTP connections are encrypted SSL sessions between your browser + and the secure site, and are meant to be reliably secure, + there is little that Privoxy can do but hand the raw + gibberish data though from one end to the other unprocessed. + + + The only exception to this is blocking by host patterns, as the client needs + to tell Privoxy the name of the remote server, + so that Privoxy can establish the connection. + If that name matches a host-only pattern, the connection will be blocked. + + + As far as ad blocking is concerned, this is less of a restriction than it may + seem, since ad sources are often identifiable by the host name, and often + the banners to be placed in an encrypted page come unencrypted nonetheless + for efficiency reasons, which exposes them to the full power of + Privoxy's ad blocking. + + + Content cookies (those that are embedded in the actual HTML or + JS page content, see filter{content-cookies}), + in an SSL transaction will be impossible to block under these conditions. + Fortunately, this does not seem to be a very common scenario since most + cookies come by traditional means. + + + + + +Privoxy runs as a <quote>server</quote>. 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 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 be defined in addition, + and using a firewall is always good too. Better safe than sorry. + + + + + +How can I temporarily disable Privoxy? + + 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. + + + + +When <quote>disabled</quote> 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 + normally be expected to do. It is still a middle-man in + the interaction between your browser and web sites. + + + + +My logs show Privoxy <quote>crunches</quote> +ads, but also its own internal CGI pages. What is a <quote>crunch</quote>? + + A crunch simply means Privoxy intercepted + something, nothing more. Often this is indeed ads or + banners, but Privoxy uses the same mechanism for + trapping requests for its own internal pages. For instance, a request for + Privoxy's configuration page at: http://config.privoxy.org, is + intercepted (i.e. it does not go out to the 'net), and the familiar CGI + configuration is returned to the browser, and the log consequently will show + a crunch. + + + + +Can Privoxy effect files that I download +from a webserver? FTP server? + + From the webserver's perspective, there is no difference between + viewing a document (i.e. a page), and downloading a file. The same is true of + Privoxy. If there is a match for a block pattern, + it will still be blocked, and of course this is obvious. + + + Filtering is potentially more of a concern since the results are not always + so obvious, and the effects of filtering are there whether the file is simply + viewed, or downloaded. And potentially whether the content is some obnoxious + advertisement, or Mr. Jimmy's latest/greatest source code jewel. Of course, + one of these presumably is bad content that we don't want, and + the other is 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 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 configuration parameters of + course. Also, documents that are of an unknown type (generally assumed to be + text/plain) can be filtered, as will those that might be + incorrectly reported by the webserver. If such a file is a downloaded file + that is intended to be saved to disk, then any content that might have been + altered by filtering, will be saved too, for these (probably rare) cases. + + + 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 not. + + + If you download text files, you probably do not want these to be filtered, + particularly if the content is source code, or other critical content. Source + code sometimes might be mistaken for Javascript (i.e. the kind that might + open a pop-up window). It is recommended to turn off filtering for download + sites (particularly if the content may be plain text files and you are using + version 3.0.2 or earlier) in your user.action file. And + also, for any site or page where making any changes at + all to the content is to be avoided. + + + Privoxy does not do FTP at all, only HTTP + and HTTPS (SSL) protocols, so please don't try. + + + + +I just downloaded a Perl script, and Privoxy +altered it! Yikes, what is wrong! + + Please read above. + + + + +Should I continue to use a <quote>HOSTS</quote> file for ad-blocking? + + One time-tested technique to defeat common ads is to trick the local DNS + system by giving a phony IP address for the ad generator in the local + HOSTS file, typically using 127.0.0.1, aka + localhost. This effectively blocks the ad. + + + 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: + + + + { +block } + www.ad.example1.com + ad.example2.com + ads.galore.example.com + etc.example.com + + + + +Where can I find more information about Privoxy +and related issues? + + &seealso; + + + + + + +I've noticed that Privoxy changes <quote>Microsoft</quote> to +<quote>MicroSuck</quote>! Why are you manipulating my browsing? + + + We're not. The text substitutions that you are seeing are disabled + in the 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! + + + + + + + + + +Troubleshooting + + +I am getting <quote>connection refused</quote> +with every web page? + + Either Privoxy is not running, or your + browser is configured for a different port than what + Privoxy is using, or, if using a forwarding + rule, you have a configuration problem or a problem with a host in the + forwarding chain. + + + + + You should verify that &my-app; is indeed running and that the correct port is set, + and matches what your browser is set to. See listen-address + option in Privoxy's main configuration file. If using + any forwarding rules, disable those to make sure the problem is not with + a forwarder. + + + + + +I just added a new rule, but the steenkin ad is +still getting through. How? + + If the ad had been displayed before you added its URL, it will probably be + held in the browser's cache for some time, so it will be displayed without + the need for any request to the server, and Privoxy + will not be in the picture. The best thing to do is try flushing the browser's + caches. And then try again. + + + + If this doesn't help, you probably have an error in the rule you + applied. Try pasting the full URL of the offending ad into http://config.privoxy.org/show-url-info + and see if it really matches your new rule. Blocking ads is like blocking + spam: a lot of tinkering is required to stay ahead of the game. + + + + + +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). + + + + If still a problem, 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. 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 a completely new section for your site. In any case, the recommended + way is to disable only the prime suspect, reload the problem page, and only + if the problem persists, disable more and more actions until you have + identified the culprit. You may or may not want to turn the other actions + on again. Remember to flush your browser's caches in between any such changes! + + + Alternately, if you are comfortable with a text editor, you can accomplish + the same thing by editing the appropriate actions file. Probably the easiest + way to deal with such problems when editing by hand is to add your + site to a { fragile } section in user.action, + which is an alias that turns off most dangerous + actions, but is also likely to turn off more actions then needed, and thus lower + your privacy and protection more than necessary, + + + Troubleshooting actions is discussed in more detail in the User Manual appendix, + Troubleshooting: the Anatomy of an Action. + There is also an actions tutorial + with general configuration information and examples. + + + + + + + +After installing Privoxy, I have to log in +every time I start IE. What gives? + + + This is a quirk that effects the installation of + Privoxy, in conjunction with Internet Explorer and + Internet Connection Sharing on Windows 2000 and Windows XP. The symptoms may + appear to be corrupted or invalid DUN settings, or passwords. + + + + When setting up an NT based Windows system with + Privoxy you may find that things do not seem to be + doing what you expect. When you set your system up you will probably have set + up Internet Connection Sharing (ICS) with Dial up Networking (DUN) when + logged in with administrator privileges. You will probably have made this DUN + connection available to other accounts that you may have set-up on your + system. E.g. Mum or Dad sets up the system and makes accounts suitably + configured for the kids. + + + + When setting up Privoxy in this environment you + will have to alter the proxy set-up of Internet Explorer (IE) for the + specific DUN connection on which you wish to use + Privoxy. When you do this the ICS DUN set-up + becomes user specific. In this instance you will see no difference if you + change the DUN connection under the account used to set-up the connection. + However when you do this from another user you will notice that the DUN + connection changes to make available to "Me only". You will also find that + you have to store the password under each different user! + + + + The reason for this is that each user's set-up for IE is user specific. Each + set-up DUN connection and each LAN connection in IE store the settings for + each user individually. As such this enforces individual configurations + rather than common ones. Hence the first time you use a DUN connection after + re-booting your system it may not perform as you expect, and prompt you for + the password. Just set and save the password again and all should be OK. + + + +[Thanks to Ray Griffith for this submission.] + + + + + + +I cannot connect to any FTP sites. Privoxy + is blocking me. + + Privoxy cannot act as a proxy for FTP traffic, + so do not configure your browser to use Privoxy + as an FTP proxy. The same is true for any protocol other than HTTP + or HTTPS (SSL). + + + Most browsers understand FTP as well as HTTP. If you connect to a site, with + a URL like ftp://ftp.example.com, your browser is making + an FTP connection, and not a HTTP connection. So while your browser may + speak FTP, Privoxy does not, and cannot proxy + such traffic. + + + To complicate matters, some systems may have a generic proxy + setting, which will silently enable various protocols, including + both HTTP and FTP proxying! So it is possible to + accidentally enable FTP proxying in these cases. And of course, if this + happens, Privoxy will indeed cause problems since + it does not know FTP. Just disable the FTP setting + and all will be well again. + + + Will Privoxy ever proxy FTP traffic? Unlikely. + There just is not much reason, and the work to make this happen is more than + it may seem. + + + + + +In Mac OSX, I can't configure Microsoft Internet Explorer to use + Privoxy as the HTTP proxy. + + Microsoft Internet Explorer (in versions like 5.1) respects system-wide + network settings. In order to change the HTTP proxy, open System + Preferences, and click on the Network icon. In the settings pane that + comes up, click on the Proxies tab. Ensure the "Web Proxy (HTTP)" checkbox + is checked and enter 127.0.0.1 in the entry field. + Enter 8118 in the Port field. The next time you start + IE, it should reflect these values. + + + + + +In Mac OSX, I dragged the Privoxy folder to the trash in order to + uninstall it. Now the finder tells me I don't have sufficient privileges to + empty the trash. + + Just dragging the Privoxy folder to the trash is + not enough to delete it. Privoxy supplies an + uninstall.command file that takes care of + these details. Open the trash, drag the uninstall.command + file out of the trash and double-click on it. You will be prompted for + confirmation and the administration password. + + + The trash may still appear full after this command; emptying the trash + from the desktop should make it appear empty again. + + + + + + +In Mac OSX Panther (10.3), images often fail to load and/or I + experience random delays in page loading. I'm using + <literal>localhost</literal> as my browser's proxy setting. + + We believe this is due to an IPv6-related bug in OSX, but don't fully + understand the issue yet. In any case, changing the proxy setting to + 127.0.0.1 instead of localhost + works around the problem. + + + + + +I get a completely blank page at one site. <quote>View Source</quote> + shows only: <markup><![CDATA[<html><body></body></html>]]></markup>. Without + Privoxy the page loads fine. + + Chances are that the site suffers from a bug in + PHP, + which results in empty pages being sent if the client explicitly requests + an uncompressed page, like Privoxy does. + This bug has been fixed in PHP 4.2.3. + + + 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 + + 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 in their PHP applications (workaround) + or upgrade to PHP 4.2.3 or later (fix). + + + + + +Why am I getting a 503 Error (WSAECONNREFUSED) on every page? + + More than likely this is a problem with your TCP/IP networking. ZoneAlarm has + been reported to cause this symptom -- even if not running. The solution is + to either fight the ZA configuration, or uninstall ZoneAlarm, and then find + something better behaved in its place. Other personal firewall type products + may cause similar type problems if not configured correctly. + + + + +My logs show many <quote>Unable to get my own hostname</quote> lines. +Why? + + Privoxy tries to get the hostname of the system + its running on from the IP address of the system interface it is bound to + (from the config file + listen-address setting). If the system cannot supply + this information, Privoxy logs this condition. + + + Typically, this would be considered a minor system configuration error. It is + not a fatal error to Privoxy however, but may + result in a much slower response from Privoxy on + some platforms due to DNS timeouts. + + + This can be caused by a problem with the local HOSTS + file. If this file has been changed from the original, try reverting it to + see if that helps. + + + + +When I try to launch Privoxy, I get an +error message <quote>port 8118 is already in use</quote> (or similar wording). +Why? + + Port 8118 is Privoxy's default TCP + listening port. Typically this message would mean that there + is already one instance of Privoxy running, and + you are actually trying to start a second Privoxy + on the same port, which will not work. (You can have multiple instances but + they must be assigned different ports.) How and why this might happen varies + from platform to platform, but you need to check your installation and + start-up procedures. + + + + + + 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 SourceForge. + Or you can simply disable the demoronizer filter. + + + + + + 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 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. + + + + + + What is the <quote>demoronizer</quote> and why is it there? + + + The original demoronizer was a Perl script that cleaned up HTML pages which + were created with certain Microsoft products. MS has used proprietary extensions + to standardized font encodings (ISO 8859-1), which has caused problems for pages + that are viewed with non-Microsoft products (and are expecting to see a + standard set of fonts). The demoronizer corrected these errors so the pages + displayed correctly. Privoxy borrowed from this + script, introducing a filter based on the original demoronizer, which in turn could + correct these errors on the fly. + + + But this is only needed in some situations, and will cause serious problems in some + other situations. + + + If you are using Microsoft products, you do not need it. If you need to view + pages with UTF-8 characters (such as Cyrillic or Chinese), then it will + cause 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. + + + + + + Why do I keep seeing <quote>PrivoxyWindowOpen()</quote> in raw source code? + + + Privoxy is attempting to disable malicious + Javascript + in this case, with the unsolicited-popups + filter. Privoxy cannot tell very well + good code snippets from bad code snippets. + + + If you see this in HTML source, and the page displays without problems, then + this is good, and likely some pop-up window was disabled. If you see this + where it is causing a problem, such as a downloaded program source code file, + then you should set an exception for this site or page such that the + integrity of the page stays in tact by disabling all filtering. + + + + + + I am getting too many DNS errors like <quote>404 No Such Domain</quote>. Why + can't Privoxy do this better? + + + There are potentially several factors here. First of all, the DNS resolution + is done by the underlying operating system -- not + Privoxy itself. Privoxy + merely initiates the process and hands it off, and then later reports + whatever the 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. + + + In any case, v. 3.0.5 includes various improvements to help + Privoxy better handle these cases. +]]> + + + + + At one site Privoxy just hangs, and starts taking + all CPU. Why is this? + + + This is probably a manifestation of the 100% cpu problem that + occurs on pages containing many (thousands upon thousands) of blank lines. The blank lines + are in the raw HTML source of the page, and the browser just ignores them. But the + pattern matching in Privoxy's page filtering + mechanism is trying to match against absurdly long strings and this becomes + very CPU-intensive, taking a long, long time to complete. Until a better + solution comes along, disable filtering on these pages, particularly the + js-annoyances and unsolicited-popups + filters. + + + + +I just installed Privoxy, and all my +browsing has slowed to a crawl. What gives? + + This should not happen, and for the overwhelming number of users world-wide, + it does not happen. I would suspect some inadvertent interaction of software + components such as anti-virus software, spyware protectors, personal + firewalls or similar components. Try disabling (or uninstalling) these one + at a time and see if that helps. + + + + + + + + Contacting the developers, Bug Reporting and Feature Requests + + &contacting; + + + + +Privoxy Copyright, License and History + + + ©right; + + + + + Portions of this document are borrowed from the original + Junkbuster (tm) FAQ, and modified as + appropriate for Privoxy. + + + + License + + &license; + + + + + + History + + &history; + + + + + + + + + + + + + + + +