Glossary
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.
Also called: UA-CH, Sec-CH-UA.
The user-agent string was one long line that everybody parsed badly, so Chromium split it up. User-agent client hints send a small set of low-entropy headers on every request — the browser brand list, whether the device is mobile, the platform name — and hold back the detailed ones until a site asks for them with an Accept-CH response header. Those high-entropy hints cover the platform version, the CPU architecture, the device model and the full browser version. The same values are readable from script through the userAgentData interface.
For anyone running separate identities this is the most common place a setup contradicts itself, because there are now two accounts of the same facts and a tool that changes only the user-agent string leaves the hints reporting the real machine. A site does not need to be clever to catch it; it just compares them. Argus generates the user-agent and the client-hint metadata together from the same preset, as part of the coordinated identity described on the fingerprints page, so the two halves agree by construction rather than by being edited in step.
More from the glossary
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.
Browser profile
A directory on disk holding everything one browsing identity owns — cookies, storage, cache, history and settings — plus, in an anti-detect browser, its fingerprint and proxy.
Residential proxy
A proxy whose exit address belongs to a consumer internet connection, which is what makes a login from it unremarkable.
Datacenter proxy
A proxy hosted in a data centre. Fast, cheap and openly identifiable as hosting, which makes it right for fetching public pages and wrong for signing in.
ISP proxy
An address registered to a consumer ISP but hosted in a data centre — datacenter speed and stability with residential registration.
Mobile proxy
A proxy exiting through a carrier network, where one address is shared by thousands of real phones — which is what makes it tolerant.
Every entry is listed on the glossary index.