Browsers send a user agent with every request: a line of text that names the browser, its engine and the operating system. Sites use it for statistics, and sometimes to decide what to show.
The box starts with yours. Copy copies it, and Copy all copies it with everything below, for example for a bug report or a support request.
Reading any user agent
Paste another user agent, from a log or an analytics tool, to read it. Use mine puts yours back, and Try an example has common ones: phones, desktops, in-app browsers, crawlers and command-line tools.
It shows the browser, its engine, the operating system and the kind of device, and says when it's a bot, a link preview or an HTTP tool.
What user agents hide
Browsers now leave some things out: Chrome gives only its major version (131.0.0.0) and "Android 10; K" on every Android phone, every Mac says macOS 10.15.7, and Windows 11 says Windows NT 10.0. The result points this out.
For your own browser, Chrome and Edge also answer "client hints", with the full version, the real operating system version, the device model and the processor. They fill in what the user agent leaves out.
On iPhone and iPad, browsers use Safari's engine, so Chrome there is WebKit, not Blink.
Your browser
What your browser tells pages besides its user agent: languages, time zone, screen and window size, touch, color scheme, and more. Nothing is stored or sent anywhere.
IPv4, IPv6 and Sent to servers come from Cloudflare, which carries this site's traffic; when a blocker stops the lookup, WebRTC finds the address through Cloudflare's STUN server. The user agent Cloudflare received should match yours. Your addresses are explained in What's My IP.
Sharing
Copy share link copies a link to this page with the user agent in it, after a #, so whoever opens it sees it read.
What's My User Agent
Your browser's user agent, read and explained: browser, engine, operating system and device. Paste any other user agent to read it too.