What is a user agent?
A user agent (UA) string is a line of text your browser sends in the User-Agent header of every HTTP request, such as "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/129.0.0.0 Safari/537.36". Servers and analytics tools read it to guess the browser, operating system and device. For historical reasons almost every UA starts with "Mozilla/5.0" and mentions several engines, which makes it hard to read by eye. Browsers are now freezing parts of the string for privacy (Windows 11 still reports "Windows NT 10.0", macOS is capped at 10.15.7) and moving detailed data to User-Agent Client Hints.
Features
- • Shows your exact user agent string with one-click copy
- • Parses browser and major version, rendering engine, OS and version, device type
- • Reads User-Agent Client Hints: brands, platform version, architecture, bitness, model
- • Analyses any pasted UA, with samples for iPhone, Android, Windows, macOS and Googlebot
- • Flags bots and crawlers such as Googlebot or headless browsers
Runs in your browser
The user agent and Client Hints are read and parsed locally with JavaScript. Nothing you paste into the analyser is uploaded or stored.