4. Quickstart to Using Privoxy
Install Privoxy. See the Installation Section below for platform specific - information. -
Advanced users and those who want to offer Privoxy - service to more than just their local machine should check the main config file, especially the security-relevant options. These are - off by default. -
Start Privoxy, if the installation program has - not done this already (may vary according to platform). See the section - Starting Privoxy. -
Set your browser to use Privoxy as HTTP and - HTTPS (SSL) proxy - by setting the proxy configuration for address of - 127.0.0.1 and port 8118. - DO NOT activate proxying for FTP or - any protocols besides HTTP and HTTPS (SSL) unless you intend to prevent your - browser from using these protocols. -
Flush your browser's disk and memory caches, to remove any cached ad images. - If using Privoxy to manage - cookies, - you should remove any currently stored cookies too. -
A default installation should provide a reasonable starting point for - most. There will undoubtedly be occasions where you will want to adjust the - configuration, but that can be dealt with as the need arises. Little - to no initial configuration is required in most cases, you may want - to enable the - web-based action editor though. - Be sure to read the warnings first. -
See the Configuration section for more - configuration options, and how to customize your installation. - You might also want to look at the next section for a quick - introduction to how Privoxy blocks ads and - banners.
If you experience ads that slip through, innocent images that are - blocked, or otherwise feel the need to fine-tune - Privoxy's behavior, take a look at the actions files. As a quick start, you might - find the richly commented examples - helpful. You can also view and edit the actions files through the web-based user interface. The - Appendix "Troubleshooting: Anatomy of an - Action" has hints on how to understand and debug actions that - "misbehave". -
Please see the section Contacting the - Developers on how to report bugs, problems with websites or to get - help. -
Now enjoy surfing with enhanced control, comfort and privacy! -
4.1. Quickstart to Ad Blocking
Ad blocking is but one of Privoxy's - array of features. Many of these features are for the technically minded advanced - user. But, ad and banner blocking is surely common ground for everybody.
- This section will provide a quick summary of ad blocking so - you can get up to speed quickly without having to read the more extensive - information provided below, though this is highly recommended.
First a bit of a warning ... blocking ads is much like blocking SPAM: the - more aggressive you are about it, the more likely you are to block - things that were not intended. And the more likely that some things - may not work as intended. So there is a trade off here. If you want - extreme ad free browsing, be prepared to deal with more - "problem" sites, and to spend more time adjusting the - configuration to solve these unintended consequences. In short, there is - not an easy way to eliminate all ads. Either take - the easy way and settle for most ads blocked with the - default configuration, or jump in and tweak it for your personal surfing - habits and preferences.
Secondly, a brief explanation of Privoxy's - "actions". "Actions" in this context, are - the directives we use to tell Privoxy to perform - some task relating to HTTP transactions (i.e. web browsing). We tell - Privoxy to take some "action". Each - action has a unique name and function. While there are many potential - actions in Privoxy's - arsenal, only a few are used for ad blocking. Actions, and action - configuration files, are explained in depth below.
Actions are specified in Privoxy's configuration, - followed by one or more URLs to which the action should apply. URLs - can actually be URL type patterns that use - wildcards so they can apply potentially to a range of similar URLs. The - actions, together with the URL patterns are called a section.
When you connect to a website, the full URL will either match one or more - of the sections as defined in Privoxy's configuration, - or not. If so, then Privoxy will perform the - respective actions. If not, then nothing special happens. Furthermore, web - pages may contain embedded, secondary URLs that your web browser will - use to load additional components of the page, as it parses the - original page's HTML content. An ad image for instance, is just an URL - embedded in the page somewhere. The image itself may be on the same server, - or a server somewhere else on the Internet. Complex web pages will have many - such embedded URLs. Privoxy can deal with each URL individually, so, for - instance, the main page text is not touched, but images from such-and-such - server are blocked.
The most important actions for basic ad blocking are: block, handle-as-image, - handle-as-empty-document,and - set-image-blocker:
block - this is perhaps - the single most used action, and is particularly important for ad blocking. - This action stops any contact between your browser and any URL patterns - that match this action's configuration. It can be used for blocking ads, - but also anything that is determined to be unwanted. By itself, it simply - stops any communication with the remote server and sends - Privoxy's own built-in BLOCKED page instead to - let you now what has happened (with some exceptions, see below). -
handle-as-image - - tells Privoxy to treat this URL as an image. - Privoxy's default configuration already does this - for all common image types (e.g. GIF), but there are many situations where this - is not so easy to determine. So we'll force it in these cases. This is particularly - important for ad blocking, since only if we know that it's an image of - some kind, can we replace it with an image of our choosing, instead of the - Privoxy BLOCKED page (which would only result in - a "broken image" icon). There are some limitations to this - though. For instance, you can't just brute-force an image substitution for - an entire HTML page in most situations. -
handle-as-empty-document - - sends an empty document instead of Privoxy's - normal BLOCKED HTML page. This is useful for file types that are neither - HTML nor images, such as blocking JavaScript files. -
set-image-blocker - tells - Privoxy what to display in place of an ad image that - has hit a block rule. For this to come into play, the URL must match a - block action somewhere in the - configuration, and, it must also match an - handle-as-image action. -
The configuration options on what to display instead of the ad are: -
pattern - a checkerboard pattern, so that an ad - replacement is obvious. This is the default. - blank - A very small empty GIF image is displayed. - This is the so-called "invisible" configuration option. - http://<URL> - A redirect to any image anywhere - of the user's choosing (advanced usage). -
Advanced users will eventually want to explore Privoxy - filters as well. Filters - are very different from blocks. - A "block" blocks a site, page, or unwanted contented. Filters - are a way of filtering or modifying what is actually on the page. An example - filter usage: a text replacement of "no-no" for - "nasty-word". That is a very simple example. This process can be - used for ad blocking, but it is more in the realm of advanced usage and has - some pitfalls to be wary off.
The quickest way to adjust any of these settings is with your browser through - the special Privoxy editor at http://config.privoxy.org/show-status - (shortcut: http://p.p/show-status). This - is an internal page, and does not require Internet access.
Note that as of Privoxy 3.0.7 beta the - action editor is disabled by default. Check the - enable-edit-actions - section in the configuration file to learn why and in which - cases it's safe to enable again.
If you decided to enable the action editor, select the appropriate - "actions" file, and click - "Edit". It is best to put personal or - local preferences in user.action since this is not - meant to be overwritten during upgrades, and will over-ride the settings in - other files. Here you can insert new "actions", and URLs for ad - blocking or other purposes, and make other adjustments to the configuration. - Privoxy will detect these changes automatically.
A quick and simple step by step example:
Right click on the ad image to be blocked, then select - "Copy Link Location" from the - pop-up menu. -
Set your browser to - http://config.privoxy.org/show-status -
Find user.action in the top section, and click - on "Edit": -
-You should have a section with only - block listed under - "Actions:". - If not, click a "Insert new section below" - button, and in the new section that just appeared, click the - Edit button right under the word "Actions:". - This will bring up a list of all actions. Find - block near the top, and click - in the "Enabled" column, then "Submit" - just below the list. -
Now, in the block actions section, - click the "Add" button, and paste the URL the - browser got from "Copy Link Location". - Remove the http:// at the beginning of the URL. Then, click - "Submit" (or - "OK" if in a pop-up window). -
Now go back to the original page, and press SHIFT-Reload - (or flush all browser caches). The image should be gone now. -
This is a very crude and simple example. There might be good reasons to use a - wildcard pattern match to include potentially similar images from the same - site. For a more extensive explanation of "patterns", and - the entire actions concept, see the Actions - section.
For advanced users who want to hand edit their config files, you might want - to now go to the Actions Files Tutorial. - The ideas explained therein also apply to the web-based editor.
There are also various - filters that can be used for ad blocking - (filters are a special subset of actions). These - fall into the "advanced" usage category, and are explained in - depth in later sections.
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