User Agent Checker
Your browser, OS, device and screen.
- Free
- No sign-up
- Private: runs in your browser
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Browser and system
Display and features
Client hints
See exactly what your browser tells websites
Every time you open a page, your browser introduces itself with a user agent string. This checker shows that string and translates it into plain facts: the browser and its version, the rendering engine, the operating system, the device type and model, and the CPU architecture. It also lists your screen resolution, the size of the browser window, pixel density, preferred languages, time zone and support for cookies, touch and other features.
Why it is useful
- Support and bug reports: copy everything as text and paste it into a ticket, so developers know exactly which browser and device you use.
- Web development and testing: confirm what a device emulator or a real phone reports, check the viewport size at different zoom levels and verify the device pixel ratio for responsive images.
- Log analysis: paste user agents from server logs or analytics into the parser to see which browsers and bots visit your site.
- Privacy awareness: see how much a site can learn about your setup without asking.
User agent reduction and client hints
Chrome, Edge and other Chromium browsers now send a reduced user agent: the minor version numbers are zeros and the operating system version is frozen, so Windows 11 reports itself as Windows 10. Websites that need more detail ask for user-agent client hints instead. When your browser supports them, the checker reads the high-entropy hints, such as the full browser version, platform version, architecture and device model, and uses them to correct the result. Firefox and Safari do not offer client hints, so their results come from the user agent string alone.
Frequently asked questions
What is a user agent?
A user agent string is a line of text your browser sends with every request. It names the browser, its version, the rendering engine and the operating system, so websites can adapt their content or log which devices visit them.
Why does my user agent mention Mozilla and Safari when I use Chrome?
For historical compatibility. Early websites checked for "Mozilla", so every browser started to include it, and Chromium browsers mention AppleWebKit and Safari for the same reason. The parser reads past these tokens to find the real browser.
What are user-agent client hints?
Chromium browsers now send a shorter, frozen user agent and offer details such as the exact platform version, device model and CPU architecture through client hints (navigator.userAgentData) instead. When available, the checker reads them, which is why it can tell Windows 11 apart from Windows 10.
Is my information stored?
No. Everything on this page is read and shown in your own browser. Nothing is sent to a server or saved.
Can I check a different user agent?
Yes. Paste any user agent string, for example from a server log or analytics report, into the box at the bottom and it is parsed in the same way.