The fingerprint you are handing out
Every site can build this without a cookie, a login or your permission.
Runs entirely in your browser — nothing is sent to us.
What a browser fingerprint is#
A fingerprint is a combination of many small facts your browser reveals to every page: its version, the screen size, the time zone, the graphics card, how it draws text. Any one of them is shared by millions of people. Together they can be rare enough to recognise a single browser across sites, with no cookie and nothing stored on your device. Clearing your cookies does nothing to it.
What this page collects#
- Browser
- User agent, languages, cookie and Do Not Track settings
- Screen
- Resolution, colour depth and pixel ratio
- System
- Platform and time zone
- Hardware
- CPU core count, device memory and touch points, where the browser reports them
- Rendering
- Hashes of a canvas drawing and an audio signal, and the WebGL vendor and renderer. Small differences in drivers and hardware make these highly individual
Everything is read in your browser and shown to you. Nothing is sent to us or stored.
Bits of entropy and how rare you are#
Each bit of entropy halves the crowd you could be in. About 33 bits are enough to single out one person among everyone alive, because 2^33 is roughly 8.6 billion. The page adds up an estimate for each signal and converts the total into "about 1 in N browsers look like yours".
What actually reduces it#
- Blend in. A mainstream browser at default settings, on a common screen size, looks like millions of others. Unusual fonts, extensions and window sizes make you stand out.
- Use a browser that standardises or randomises values. The Tor Browser standardises them. Firefox has a
privacy.resistFingerprintingsetting. Some browsers add small random noise to canvas and audio readings, which is what the "randomised canvas" demo on the page shows: a hash that changes every time is worthless as an identifier. - Block third-party scripts. Most fingerprinting code runs in trackers, not in the sites you chose to visit.
Your IP address is only one of the signals a site combines with these. See how websites see your IP address, and try the HTTP header viewer to see what the browser sends before any script runs.
Related guides
- How websites see your IP addressEvery site you visit receives your public IP address. Where it comes from, how proxies and CDNs pass it along, what else is sent with it, and what a VPN changes.
- Can an IP address reveal your location?No. IP geolocation is an estimate built from registry data and inference, often correct to the country and rarely to the street. How it works and why it goes wrong.