Browser
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Version —
Free network tool
What is my user agent?
See the UA your browser sends, compare HTTP vs JavaScript, read Client Hints, and paste any string to decode browser, OS and device.
Paste any UA from logs or pick an example. Decode updates the cards below instantly.
Quick examples
smart_toy
Bot detected
Showing: Your live browser
Core engine
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Layout engine
Device type
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Classified from UA tokens
Platform / OS
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Version —
HTTP header (this request)
Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; [email protected])
Client Hints
Checking navigator.userAgentData…
What is a user agent?
A user agent is a short text string your browser (or bot, script, or app) sends so servers know how to format pages. It appears as the HTTP User-Agent header and in JavaScript as navigator.userAgent.
Modern browsers are freezing parts of that string and moving detail into Client Hints. This page shows both so you can see what sites actually receive.
How to use this tool
- Your live UA is loaded in the box automatically. The four cards show browser, engine, device and OS.
- Click Decode after editing, or pick an example chip — results update immediately.
- Use Reset to my UA to restore your real browser string.
- Compare the HTTP header panel with JavaScript — a mismatch often means a privacy extension or proxy rewrite.
Why every string starts with Mozilla/5.0
Legacy servers sniffed for “Mozilla” to send modern HTML. Other browsers copied the prefix. It remains for compatibility even though it no longer identifies Netscape.
HTTP header vs JavaScript
Normally both match. Extensions, anti-detect browsers, or reverse proxies can change one side. This page flags that mismatch so you notice spoofing or privacy tools.
Client Hints and Windows 11
Chromium browsers expose navigator.userAgentData. High-entropy fields include architecture and platformVersion. Windows 11 still reports Windows NT 10.0 in the classic UA; platformVersion 13+ means Windows 11 when hints are available.
Bots and crawlers
Googlebot, Bingbot, ClaudeBot, curl and similar clients advertise themselves. Paste a log line into the decoder to classify it. Never trust UA alone for security — verify official bots with reverse DNS when needed.
Privacy note
Parsing runs in your browser. The HTTP UA is whatever your request already sent to our server (like any website). We do not create an account from this tool. See the Privacy Policy for logs.
FAQ
What is a user agent string?
A user agent (UA) string is a short text your browser sends so servers know roughly which browser and operating system you use. It appears in the HTTP User-Agent header and in JavaScript as navigator.userAgent.
How do I find my user agent?
Open this page — your live UA is shown at the top. You can also check developer tools → Network → request headers, or type navigator.userAgent in the browser console.
Why does every user agent start with Mozilla/5.0?
Historical compatibility. Early browsers pretended to be Mozilla so servers would send modern pages. The prefix stuck even though today’s browsers are not Mozilla.
Can I change my user agent?
Yes via extensions or developer tools, but many sites also use Client Hints and fingerprinting. Spoofing the UA alone rarely makes you anonymous.
What are Client Hints?
User-Agent Client Hints are structured fields (brands, platform, architecture) that replace bits of the frozen UA string. Chrome-based browsers expose them via navigator.userAgentData.
Why does Windows 11 show as Windows 10?
The classic UA still says Windows NT 10.0 on Windows 11. Client Hints platformVersion 13 or higher indicates Windows 11. This page checks both when available.
Can websites track me with my user agent?
A UA alone is shared by millions of users, so it is a weak identifier. Combined with IP, cookies and fingerprint signals it still helps profiling. Reducing uniqueness helps but is not complete privacy.
What is a bot user agent?
Crawlers such as Googlebot or curl send distinctive UA strings. Sites use them for analytics and access control. This tool flags common bot patterns when you paste a UA.
How do I read a user agent string?
Look for the browser token (Chrome/, Firefox/, Version/…Safari/), the OS token (Windows NT, Android, Mac OS X), and optional device hints. This page parses those fields for you.
Is spoofing a user agent legal/safe?
Changing your own UA for testing is generally fine. Using spoofing to bypass terms, commit fraud, or evade security controls can violate laws or site rules. Prefer honest testing accounts.