Overview
- The update is live in Private Browsing Mode and when Enhanced Tracking Protection is set to Strict, with a per‑site toggle for users who encounter breakage.
- Phase 2 spoofs or limits key signals by blocking local fonts except select language sets, coarsening touch reporting to 0, 1, or 5, and reporting available screen height as 48 pixels less than actual.
- Firefox now adds random noise when sites read back background images, a tactic aimed at blunting canvas-based fingerprinting.
- Reports differ on how CPU cores are spoofed, with BleepingComputer and Dataconomy citing a constant two cores while PC Gamer describes four‑ or eight‑core reporting.
- Mozilla says Phase 1 cut unique fingerprintability from about 65% to 35%, and Firefox 145 also drops the 32‑bit Linux build due to low demand.