Mozilla rolls out ad blocking to Firefox for iOS

As detailed in The Register, Mozilla has begun rolling out its native ad blocking feature to the iOS version of its popular Firefox browser, moving it out of its experimental phase. This development comes after several weeks of anticipation and required Mozilla to adapt its approach due to architectural differences in iOS.

Due to Apple's requirement for all iOS browsers to use its WebKit engine, Mozilla had to build ad blocking directly into Firefox for iOS. This implementation utilizes Apple's WebKit Content Blockers, which operate differently from traditional JavaScript-based extensions. Apple's framework requires content blocking rules to be defined declaratively in a structured format, which is then converted to bytecode. Mozilla integrates this by converting its EasyList filter into a JSON file for WebKit.

The ad blocking feature is off by default and can be enabled through the in-app settings. Once activated, it will block ads from third-party networks, pop-ups, and overlays, but not ads on search results or sponsored content on Firefox's home or new tab pages. Ads served directly by websites may also not be blocked. Mozilla has stated it has no plans to expand built-in ad blocking to desktop or Android versions of Firefox, continuing to support the existing ecosystem of ad-blocking extensions.

Source: The Register