Firefox is now the last major browser that still supports uBlock Origin

Mozilla has confirmed that it will keep supporting uBlock Origin, the most widely used ad-blocking extension, at a moment when Microsoft Edge is preparing to cut off extensions built on the older Manifest V2 architecture. In a Bluesky post dated August 10, 2026, the Firefox team wrote: “Our support for uBlock Origin isn't going anywhere.” According to PCWorld, the statement came in response to Microsoft's decision.

A shift across the Chromium ecosystem

Microsoft is following the lead of Google, which began the migration from Manifest V2 to Manifest V3 in Chrome and Chromium. Because Edge is built on Chromium — the open-source engine that also powers Opera, Brave, Vivaldi and Samsung Browser — the change affects most of the browser market. Under Manifest V3, ad-blocking extensions lose access to the APIs needed to reliably identify and block ads, including those shown on websites and inside video players.

Firefox is one of the few browsers that is not based on Chromium, and it is now the only major browser in which uBlock Origin still runs. Neither Safari nor DuckDuckGo, the two other notable non-Chromium browsers, support the extension.

What users are left with

Anyone who wants full-strength blocking now has to pick Firefox. On other browsers the practical options are uBlock Origin Lite, which offers fewer features and weaker blocking, or the built-in ad-blocking tools that browsers ship with. Social media reaction was blunt: “This is officially Firefox's killer app,” one Bluesky user wrote, adding that they would never go back to Chrome as long as uBlock Origin is supported on Firefox.

The article was originally published by PCWorld's sister publication PC för Alla and translated and localized from Swedish.