What is my user agent? See your browser’s User-Agent string
Your user agent is a short line of text your browser sends with every request to say which browser, version and operating system it is. This page shows your User-Agent string exactly as websites receive it, what it says about your browser, operating system and device, and the newer Client Hints that Chromium browsers send alongside it. Nothing you see here is stored.
Your User-Agent string
Reading…- Browser
- …
- Rendering engine
- …
- Operating system
- …
- Device type
- …
- Names itself as a bot or automated browser
- …
Client Hints
Reading…
What is a user agent string?
Every time your browser loads a page, it sends a User-Agent header. Pages can also read the same value in JavaScript as navigator.userAgent. A typical string names the browser and its version, the rendering engine and the operating system, for example "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36".
The format is historical. Almost every browser starts with "Mozilla/5.0" and many mention engines they are not, so that old websites keep working. That is why a parser has to check the tokens in a careful order.
User-Agent Client Hints
Chrome, Edge, Opera and other Chromium browsers now freeze parts of the User-Agent string: Windows 11 still reports "Windows NT 10.0", every Mac reports macOS 10.15.7, and the minor version is often zeros. The detail moved to User-Agent Client Hints, which a page can request in JavaScript through navigator.userAgentData. Firefox and Safari do not support Client Hints, so the box stays empty there.
What websites use the user agent for
- Serving the right download, layout or video format for your device.
- Statistics: which browsers and versions visitors use.
- Recognising search engine crawlers and other bots, which name themselves in the user agent.
- Security: a user agent that contradicts what the browser can actually do is a common sign of a script or a spoofing extension.
Can I change my user agent?
Yes. Browser developer tools and extensions can send any string you like, and automation tools can set it in one line. Changing it does not change the rest of what your browser reveals, such as screen, fonts, graphics and time zone, so a site can still notice that the claimed browser does not match the real one.
See what else your browser reveals: run the browser fingerprint test →
Frequently asked questions
What is my user agent?
It is the User-Agent string shown at the top of this page: the exact text your browser sends to every website to name its browser, version and operating system.
Why does my user agent say Windows 10 when I have Windows 11?
Chromium browsers stopped updating that part of the string, so Windows 10 and Windows 11 both report "Windows NT 10.0". The platform version in Client Hints tells them apart.
Why does every user agent start with Mozilla/5.0?
For compatibility. In the 1990s websites sent better pages to Mozilla-compatible browsers, so other browsers started to claim Mozilla too, and the habit stayed.
Is it safe to share my user agent?
Yes. Every website you visit already receives it. It contains no name, account or IP address.
Your user agent is only the start
Websites can recognise your browser from much more than one header, even without cookies. See the visitor ID your browser gets.
Run the browser fingerprint test