What Is My User Agent
The full string your browser sends with every request, plus everything else it announces on request.
What this page read
🖐️ One vector is not a fingerprint
Nothing on this page identifies you on its own - it describes a class of machine. What makes a browser recognisable is several stable signals at once, which is what the full test measures and scores.
🖐️ Run the full fingerprint testWhat Is My User Agent
Your User-Agent is a line of text sent with every HTTP request, naming your browser, its version and your operating system. It is the oldest identifying header on the web and the most quoted, but on its own it is weak - millions of people send the same string. What makes this page worth reading is everything listed alongside it: the values your browser will hand over to any script that asks, without a prompt.
Why the User-Agent alone is weak and the set is not
A current Chrome on a current Windows sends a string shared with an enormous number of other people, so by itself it narrows you down very little. The values beneath it are the ones that matter. Core count, device memory, screen geometry and pixel ratio, timezone and language list are each unremarkable in isolation, and jointly they describe a configuration that a small number of visitors share. That is the standard shape of fingerprinting: no single line is sensitive, and the combination is.
Client Hints replaced part of it
Browsers have been shortening the User-Agent string for years, freezing parts of it to stop it growing more identifying. The information did not disappear - it moved to User-Agent Client Hints, which sites request explicitly. Where your browser supports them, the brand and version list appears in the readout below. The practical effect is that the header got less informative while the platform overall did not.
What changing it achieves
Spoofing the User-Agent is easy and rarely helps. A string that disagrees with the other signals - claiming iPhone while reporting eight cores, a desktop resolution and a Windows platform - is more distinguishing than the honest value, because inconsistency is itself rare and detectable. If your goal is to be harder to recognise, the productive direction is a browser that reports common values consistently, not a spoofed header on top of an otherwise unchanged profile.
What Is My User Agent - FAQ
Common questions about this specific signal.
What is a user agent string?
It is a line of text your browser includes with every request, identifying the browser, its version and the operating system it runs on. Servers use it to decide which version of a page to send and to collect compatibility statistics. It is also the oldest signal in the fingerprinting toolkit, though a weak one, because so many people send an identical string.
Should I change or spoof my user agent?
Usually not. A spoofed string that contradicts your other signals is easier to notice than an honest one - claiming to be a phone while reporting a desktop screen, eight cores and a Windows platform is a combination almost nobody legitimately has. Detecting that mismatch is straightforward, and being one of the few visitors with an inconsistent profile makes you more identifiable rather than less.
What are User-Agent Client Hints?
They are a replacement mechanism for the information browsers have been removing from the User-Agent string. Rather than sending everything with every request, the browser sends a short header and provides more detail - brand, version, platform - when a site explicitly asks. The design gives browsers a place to apply policy, though in practice the information remains available to sites that request it.
Does my user agent reveal my IP address or location?
No. The User-Agent describes software, not network position. Your address is visible separately because it is part of the connection itself, and your approximate location is derived from it. The timezone and language values on this page are a different matter: they are set by your system and often contradict a VPN exit in another country, which is a mismatch worth checking with the VPN identity test.
🧰 Related tests
Every test runs entirely in your browser - nothing is stored unless you choose to share the result.