Firefox 149 ships adblock-rust, Brave’s Rust-based ad-blocking engine, disabled by default with no UI or filter lists – absent from Mozilla’s release notes.
Key Takeaways
adblock-rust is written in Rust (MPL-2.0) and handles network request blocking, cosmetic filtering, and uBlock Origin-compatible filter list syntax.
The change landed via Bugzilla Bug 2013888, filed by Mozilla engineer Benjamin VanderSloot, titled “Add a prototype rich content blocking engine.”
Disabled by default; enabling requires toggling privacy.trackingprotection.content.protection.enabled in about:config and manually supplying EasyList/EasyPrivacy filter list URLs.
Waterfox has already adopted adblock-rust, building directly on Firefox’s own implementation.
Brave VP of Privacy Shivan Kaul Sahib surfaced the integration via blog post; Mozilla made no mention in Firefox 149 release notes.
Hacker News Comment Review
Top concern: the integration could be a stepping stone toward dropping MV2 addon support, with native blocking cited to justify a gradual shift toward an “acceptable ads” model.
Open technical question whether uBlock Origin for Firefox could be updated to use adblock-rust internally rather than running as a separate, parallel engine.
