Inspect any browser User-Agent string. Detect the browser, version, OS, and device.
100% in your browser · No uploadsUser-Agent Parser decodes the User-Agent string your browser sends to every website. See the detected browser, version, rendering engine, operating system, and device type.
Easily — it's just an HTTP header. Don't rely on it for security; use proper authentication for anything sensitive.
Historical accident. Every modern browser includes 'Mozilla/5.0' for compatibility with old sites that sniffed for it.