User-Agent Parser & Generator
Paste any User-Agent string to break it down into browser, rendering engine, OS and device type — or pick a preset UA string for testing.
What is a User-Agent string?
The User-Agent HTTP header identifies the browser, rendering engine, operating system and device sending a request. Servers use it for analytics, feature detection and (increasingly) bot/crawler identification — for example distinguishing Googlebot from a real visitor.
How to use this tool
- Paste any User-Agent string into the parser to see its browser, engine, OS and device type broken out.
- Click any preset below to copy a ready-made UA string for testing — desktop browsers, mobile devices, and common search/AI crawlers.
Frequently Asked Questions
Can a User-Agent string be faked?
Yes, trivially — browser devtools, extensions and any HTTP client let you set an arbitrary UA string. Never treat the User-Agent header as a security control; it's useful for analytics and graceful feature degradation, not authentication.
Why do so many User-Agent strings still say "Mozilla"?
It's a historical compatibility artifact from the 1990s browser wars — sites checked for "Mozilla" to serve modern pages, so every subsequent browser kept the prefix to avoid being treated as legacy.