Mozilla quietly shipped adblock-rust in Firefox 149, the same Rust-based engine powering Brave's ad blocker, but left it disabled without any user interface. A new community extension called electricant/adblock-rust-manager finally exposes this hidden functionality through a proper graphical interface.

The extension provides one-click ETP toggling via Firefox's standard privacy API, plus a filter list manager supporting eight preset lists including EasyList, EasyPrivacy, and uBO Annoyances. Users can also import custom filter lists, with the extension automatically building the required pipe-separated configuration values.

Since standard WebExtensions cannot modify arbitrary about:config preferences, the tool guides users through a brief manual setup process. This involves enabling two hidden preferences that control whether the engine runs and which filter lists to apply. The guided workflow includes copy buttons for each configuration value.

This workaround demonstrates the gap between Firefox's experimental features and user accessibility. While Mozilla keeps adblock-rust disabled by default without documentation, the extension offers power users a way to leverage the same content-blocking technology that Brave has refined for years.