Editing Ad blocking (section)

===External programs===
{{Unreferenced section|date=April 2023}}
A number of external software 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 that may be offensive, inappropriate, or even malicious ([[Drive-by download]]). Popular proxy software which blocks content effectively include [[Netnanny]], [[Privoxy]], [[Squid (software)|Squid]], and some [[content-control software]]. The main advantage of the method is freedom from implementation limitations (browser, working techniques) and centralization of control (the proxy can be used by many users). Proxies are very good at filtering ads, but they have several limitations compared to browser-based solutions. For proxies, it is difficult to filter [[Transport Layer Security]] (TLS) (<code><nowiki>https://</nowiki></code>) traffic and full webpage context is not available to the filter. As well, proxies find it difficult to filter [[JavaScript]]-generated ad content.