Paste any User-Agent string to see what it tells a website about you: browser, engine, OS, device, CPU architecture, and whether it looks like a bot. We pre-fill your current UA. 100% client-side — nothing leaves your browser.
The User-Agent is a string your browser sends with every HTTP request. Historically it advertises the browser, rendering engine, OS and device so servers could serve the right content. Over the years it became a huge compatibility-theatre string that mentions "Mozilla", "Gecko" and "Safari" even when you're on Chrome — because old sites sniffed for those keywords.
Modern Chromium browsers are slowly replacing the UA string with Client Hints — small, structured headers
(sec-ch-ua, sec-ch-ua-platform, sec-ch-ua-mobile) that are harder to spoof for fingerprinting but just as useful
for feature detection.
Can I spoof my User-Agent?
Yes, most browsers expose devtools or extensions for UA spoofing. It rarely helps — other signals (Client Hints, fingerprints, TLS handshakes) contradict the spoofed UA.
Why is my browser listed as "Mozilla"?
The UA starts with "Mozilla/5.0" on nearly every browser for backwards compatibility. The real browser name is later in the string (Chrome, Safari, Firefox, etc.).
Is my UA logged by this site?
The analysis here runs entirely in your browser. Your UA is sent (like on any site) when your browser requests this page, but we don't persist it.