What information your browser can expose

A website needs some information to work

The browser exposes capabilities and preferences that allow a page to adapt: language, screen size, time zone, graphics support and other properties. Many are normal and necessary for compatibility.

The combination can form a fingerprint

When many signals are combined, they can help distinguish one browser from others. Actual uniqueness depends on the population used for comparison and cannot responsibly be claimed without maintaining a comparison dataset.

Our test does not build that database

The main audit shows signals available in the current session and does not assign a uniqueness score or store a persistent fingerprint. Separately, an optional test can show the IP, headers and network data received by our Worker only when the user runs it.