Large-Scale Measurement and Real-World Mitigation of Web Browser Fingerprinting in the Wild

With the help of almost 25 million Firefox release users, we measured how identifiable browsers really are, found which characteristics make them unique, and used that to design the fingerprinting protections that shipped in Firefox 143. Here you can read the paper and its key findings, browse the full appendix data the PDF had no room for, download the privacy-preserving aggregate data and analysis code, learn how the data was collected, and run an interactive test that compares your own browser against the measured population. If you have a question the data could answer, there is also a discussion board for proposing follow-up research.

Browser fingerprinting is a known tracking mechanism on the modern web, but its real-world effectiveness toward users has been hard to measure. To build robust protections, we measured uniqueness across a large, unbiased population, to determined what individual metrics cause users to be unique.