DevTulz Online

User Agent Parser

What is a User Agent?

The User-Agent header is a string sent by browsers, bots, and HTTP clients to identify themselves to servers. It contains the browser name and version, operating system, device type, rendering engine, and sometimes additional platform details. A typical Chrome User-Agent looks like: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36. Despite the confusing historical accumulation of tokens (most browsers claim to be Mozilla and Safari for compatibility reasons), User-Agent strings encode useful information for analytics, device detection, content negotiation, and debugging.

How to Use the User Agent Parser

  1. The tool automatically detects and displays your current browser's User-Agent.

  2. Or paste any User-Agent string to parse it.

  3. The tool identifies: browser name and version, operating system, device type, and rendering engine.

  4. Copy the parsed results for debugging or logging.

Frequently Asked Questions

Why do browsers claim to be Mozilla/5.0? Historical browser wars created a legacy: early browsers identified themselves to get content intended for popular browsers. Chrome includes 'Safari' and 'AppleWebKit' for similar reasons. User-Agent strings are now a mess of historical compatibility tokens rather than accurate self-descriptions.

Can I trust User-Agent for browser detection? User-Agents are client-controlled and can be spoofed. They're reasonably accurate for real browsers, but malicious actors or crawlers can set any User-Agent string. Use feature detection in JavaScript (not User-Agent sniffing) for browser capability checks.

What is the Sec-CH-UA header? Sec-CH-UA is part of the Client Hints API, a newer and more structured way for browsers to declare their identity. Unlike the verbose User-Agent string, Client Hints provide specific hints on demand and are harder to spoof. Chrome and Edge support it; Firefox and Safari have limited support.

Keywords: user agent parser, UA parser, browser detection, parse user agent string, user agent detector, what is my user agent, browser user agent, UA string decoder