Parse any user agent string to identify browser, operating system, device type, and rendering engine.
A user agent string is a text identifier sent by your browser to every website you visit. It contains information about your browser, operating system, device, and rendering engine. Websites use this to serve optimized content for different browsers and devices.
Yes. Your browser sends a user agent string with every HTTP request. This reveals your browser name, version, operating system, and sometimes device information. You can use browser extensions to spoof your user agent for privacy.
Historical compatibility. When Netscape Navigator (codenamed Mozilla) was dominant, servers would serve better content to "Mozilla" browsers. Other browsers started claiming to be "Mozilla-compatible" to receive the same content. This practice stuck.