Mozilla has integrated Brave's open-source, Rust-based ad and tracker blocking engine into Firefox 149, according to a report from itsfoss.com.
The update, which arrived without mention in the official release notes, includes the 'adblock-rust' technology. This engine, originally developed for the Brave browser, handles network request blocking and cosmetic filtering using a syntax compatible with uBlock Origin.
Shivan Kaul Sahib, the VP of Privacy and Security at Brave, highlighted the change in a recent blog post. The implementation was tracked via Bugzilla entry 2013888, a task handled by Mozilla engineer Benjamin VanderSloot.
Experimental implementation
Currently, the engine functions as a prototype. Mozilla has kept the feature disabled by default, meaning it lacks a user interface or pre-configured filter lists for the average user. The implementation serves as a foundational layer for future content protection features.
The news also indicates a growing trend toward shared core technologies in the browser ecosystem. According to itsfoss.com, Waterfox—a popular Firefox fork—has already adopted adblock-rust, building directly upon the implementation found in Firefox.
Users interested in testing the prototype can manually enable it through the browser's advanced configuration settings. By navigating to `about:config` and toggling `privacy.trackingprotection.content.protection.enabled` to 'true', the engine can be activated.
To make the engine functional, testers must also manually add filter lists. The source suggests adding the EasyList and EasyPrivacy URLs to the `privacy.trackingprotection.content.test_list_urls` configuration string.
When active, the engine performs the heavy lifting of stripping ad content while leaving the page layout intact. In testing on sites like Yahoo, the engine successfully blocked ad content, leaving behind only 'Advertisement' placeholders where the banners previously resided.
