From Wikipedia, the free encyclopedia

Ad filtering or ad blocking is a service which removes or alters advertising content in a webpage. This content can be represented in a variety of ways including pictures, animations, text, or pop-up windows. More advanced filters allow fine-grained control of advertisements through features like blacklists, whitelists, and regular expression filters. Certain security features also have the effect of disabling some ads.

The immediate benefits include cleaner looking webpages free from advertisements and lower resource-usage (bandwidth, CPU, memory, etc.). One drawback is that advertisements are a major source of revenue for many websites. However, the actual loss of revenue, when present, is difficult to measure.

Contents 1 Browser integration 2 External programs 3 Hosts file 4 Common advertising techniques 5 See also 6 External links

Almost all modern web browsers include a pop-up blocker. Opera and Konqueror also include content filtering, which prevents external files such as images or JavaScript files from loading. Content filtering can be added to Mozilla Firefox and related browsers with Adblock or Adblock Plus, and a number of sources provide regularly updated filter lists. Another method for filtering advertisements uses CSS rules to hide specific HTML and XHTML elements.

A number of external applications offer ad filtering as a primary or additional feature. A traditional solution is to customize an HTTP proxy (or web proxy) to filter content. These programs work by caching and filtering content before it is displayed in a user's browser. This provides an opportunity to remove not only ads but also content which may be offensive or inappropriate. Popular proxy software which block content effectively include Privoxy, Squid, Proximodo, Adextinguisher, Ad Muncher, Guidescope, IE7pro for IE7 and Proxomitron.

Further information: hosts file.

• Pop-up ads
• Plain text
• Ad banners
• Flash animations
• Keyword hyperlinks (for example Vibrant Media's IntelliTXT[1])
• Browser plugins/extensions (often labeled as adware)
• External applications (see adware, spyware)

• Online advertising
• Adblock extension for Mozilla Firefox
• Scroogle, a screen scraping proxy that allows users to perform Google searches without receiving Google advertisements
• Hosts file filtering
• Ad Muncher, a shareware ad remover which works for any program that uses the Internet. Filter list is updated every couple of days.

• DoubleClick Warns Against Ad-Blocking Browsers
• Ad blocking with ad server hostnames