User Agent Parser is a free tool that reads a user agent string and tells you the browser and version, rendering engine, operating system and type of device. Paste one from your server logs or analytics, or check your own browser with one click. The string is parsed in your browser.
How to use it
- Paste a user agent string, or click Use my browser’s user agent.
- The browser, engine, operating system and device type are shown instantly.
Reading a user agent
A typical string looks likeMozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/140.0.0.0 Safari/537.36. Most of it is historical baggage kept for compatibility: nearly every browser claims to be “Mozilla”, and Chrome also mentions Safari. The useful parts are the operating system in brackets and the last product name with its version.
Limitations
- Browsers now “freeze” parts of the user agent for privacy. Chrome, for example, reports Windows 10 even on Windows 11 and hides minor versions.
- User agents are easy to fake, so never use them for security decisions.
- For reliable feature support, test for the feature in JavaScript instead of checking the browser name.
To see everything else your browser sends with each request, paste the request headers into theHTTP Headers Analyzer; for cookies, use theCookie Parser.
Frequently asked questions
What is a user agent?
A short text every browser sends with each request, describing the browser, its version and the operating system. Servers use it for statistics and compatibility.
Why does every browser say “Mozilla”?
For historical compatibility: in the 1990s, sites only sent modern pages to Netscape (“Mozilla”), so other browsers copied the name. It has meant nothing for decades.
Can I trust the user agent?
Not for security. It’s easy to change, and browsers increasingly freeze or simplify it for privacy, so detailed versions and device models may be approximate.
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