Privoxy is an open-source, non-caching Web proxy that can run on nearly any major Web browser. The program can modify Web pages and HTTP headers as an intermediary between the browser display and the Web source. Privoxy is useful in helping Web users tailor their results when loading various pages.
Techopedia explains Privoxy
One of the main uses of Privoxy is to limit "Internet junk" such as pop-up ads and other distractions. The Web proxy intercepts and scrubs these items from the page load in the browser. Users can take advantage of Web page filtering where banner ads and other elements can be altered or removed.
Privoxy includes easy HTML templates for filtering Web content. The program has also gotten attention for its flexibility in targeting exclusive changes at certain sites and pages. Successive versions have fewer errors and are easier to use. Some problems include consistent operation with computer reboots and errors with browsing if Privoxy is uninstalled.