Firefox 143

Mozilla, with the University of Toronto and UC San Diego, ran a large-scale browser fingerprinting study across nearly 25 million Firefox release users to quantify real-world identifiability and isolate which characteristics make users unique. The findings directly shaped the fingerprinting protections shipped in Firefox 143, and the team released the paper, full appendix data, privacy-preserving aggregate datasets, analysis code, and an interactive self-test tool.