The ad blocker moved inside the browser.

Firefox for iOS moved an ad blocker inside the browser.

A Hacker News post about the rollout reached 637 points, and Mozilla's Firefox for iOS 153.0 release page confirms the current iOS release line. The feature is experimental, rolling out gradually, and turned off by default. 123

Firefox already had Enhanced Tracking Protection. That feature focuses on trackers that follow people across sites. The new Ad Blocker focuses on the ad request itself, so an ad that carries no tracking code can still be visible under tracking protection alone. 4

The new path is network-level: Firefox compares ad-related destinations with a filter list based on EasyList and can stop many requests before their payload loads. That is a different mechanism from downloading an ad and hiding its pixels afterward. 34

The boundary matters. Search ads on Google, Bing, and DuckDuckGo remain outside the filter, and sponsored content on Firefox's home screen or new tabs is handled separately. Websites can also use ad-delivery paths that do not match the list. 34

The useful takeaway is narrower than "Firefox blocks ads now": on iOS, the browser itself is becoming the gate that decides which ad requests get a chance to arrive. That gives Mozilla tighter control over defaults and exceptions, while leaving coverage partial and opt-in. Neowin also places the move in a wider browser shift as Google and Microsoft reduce support for Manifest V2 extensions. 3