User-Agent Parser

The User-Agent string a browser sends with every request looks like a chaotic mix of names and versions, largely because of browsers' historical habit of impersonating each other (nearly every modern browser's string still contains "Mozilla/5.0"). This tool breaks it down into browser, engine, OS, and device type.

How to use it

• Paste a User-Agent string (from your own dev tools console or from server logs) and it's parsed instantly.
• The result shows the browser name and version, the rendering engine, the operating system, and the device type (desktop, mobile, tablet, bot).
• Handy for recognizing bot and crawler strings (Googlebot, Bingbot, etc.), which also send a User-Agent.

Common uses

• Debugging a bug that only shows up in a specific browser or OS — quickly figuring out what the user was actually on from a log entry.
• Analyzing server logs for the share of mobile traffic or outdated browsers among visitors.
• Checking whether a request genuinely came from a legitimate search bot, rather than someone spoofing its User-Agent.

Things to keep in mind

A User-Agent is entirely controlled by the client and easy to spoof — don't rely on it for security decisions.

Under the User-Agent Reduction effort, modern browsers increasingly freeze or simplify OS and device details for privacy — detection accuracy is gradually declining.