Glossary
Browser fingerprint
The set of properties a page can read about your browser and machine in a few milliseconds, without permission, which together identify the device.
Also called: device fingerprint, browser fingerprinting.
A browser fingerprint is not one number. It is a few dozen properties a page reads in a few milliseconds, without a permission prompt and without leaving anything behind: the platform string, the language list, the timezone, the screen geometry, the reported device memory and CPU core count, the fonts available, and the hashed output of the graphics and audio stacks. Its value to a site is that it survives the things a visitor does to reset themselves — clearing cookies changes nothing, and neither does a new IP address.
The operational point, and the one that costs people accounts, is that a fingerprint is judged as a set. The question a site asks is not whether a value is unusual but whether the values together describe a machine that could exist. A user-agent claiming macOS beside client-hint metadata that says Windows describes no real computer; neither does a 4K screen beside two CPU cores and a timezone three hours from the exit IP. Scrambling fields independently makes this worse, not better, because every extra random field is another chance for two of them to contradict. Argus generates the identity as one coherent set and applies it in the renderer — the fingerprints page walks through what is measured and where the substitute lands.
More from the glossary
Canvas fingerprint
An identifier derived by asking the browser to draw a shape or a line of text and hashing the exact pixels that come back.
WebGL fingerprint
An identifier built from the graphics hardware a page can see through WebGL — the reported vendor and renderer strings, plus the pixels a 3D scene produces.
Audio fingerprint
An identifier derived from processing a synthesized tone through the browser's audio stack and hashing the numbers that come out.
WebRTC leak
A page reading your real IP address out of WebRTC's connection setup, bypassing the proxy the rest of the browser is using.
User-agent client hints
Chromium's structured replacement for the user-agent string: a set of Sec-CH-UA request headers and a JavaScript API that report the browser, platform and hardware separately.
Cookie jar
The store a browser keeps cookies in. Everything sharing one jar shares one identity, which is why isolation is a property of the jar and not of the tab.
Every entry is listed on the glossary index.