About this tool
Every request a browser makes carries a User-Agent string — a dense, oddly-formatted line that names the browser, its engine, the operating system and often the device. It is easy to misread by eye. This parser breaks it into clean fields: browser and version, rendering engine, OS, device type and CPU architecture. Click “use my browser” to inspect your own, or paste one from a server log.
It uses a well-known parsing library entirely in your browser, so nothing is sent anywhere. Handy for debugging analytics, checking device-detection logic or just satisfying curiosity about a log line.
Frequently asked questions
Is User-Agent detection 100% reliable?
No. It is a best-effort read of a string the browser chooses to send. Many modern browsers now freeze or simplify their User-Agent for privacy (User-Agent reduction), so version numbers and OS details can be generic or missing.
Can a User-Agent string be faked?
Easily — any browser devtools, an extension, or a simple HTTP client can send an arbitrary User-Agent. Never rely on it for security decisions, only for rough analytics or feature detection.
Is my User-Agent string sent anywhere?
No. Parsing happens locally in your browser with JavaScript — pasted strings are not transmitted anywhere.
Where do I get a User-Agent string to test?
Click 'Use mine' to parse your own browser's string, or paste one from server access logs, analytics, or a bug report to see how it breaks down.
Why do some fields show '—'?
It means that piece of information isn't present in the string or wasn't recognized — common for unusual bots, embedded webviews, or a User-Agent that's been reduced or frozen by the browser.