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User Agent Parser

Identify browser, OS, and device from any user agent string

Every time your browser requests a page, it introduces itself with a line of text called the user agent string — and that line is hard to read by eye. This parser breaks any UA string into labeled facts: browser name and version, operating system, device type, and rendering engine. Paste a string from your logs, or analyze your own browser to see what websites learn about you.

How to Use

  • Analyze your browser: Your current UA is detected and parsed automatically
  • Paste a string: Drop any UA string from logs or error reports into the input
  • Read the breakdown: Browser, version, OS, device type, and engine appear as separate fields
  • Spot bots: Crawlers like Googlebot, Bingbot, and Baiduspider are identified by name

Features

  • Detects Chrome, Firefox, Safari, Edge, Opera, and Internet Explorer
  • Recognizes desktop and mobile operating systems
  • Identifies common search engine crawlers
  • Handles tricky cases like Edge, whose UA also contains “Chrome”
  • Instant, fully client-side parsing — the string never leaves your browser

What Is in a User Agent String?

A typical UA is a chain of product tokens with versions, and much of it is historical baggage: the leading “Mozilla” is a nod to Netscape-era compatibility, and Chrome mentions Safari so old browser-sniffing code keeps working. The useful parts are the OS token in parentheses and the final browser token. Remember the UA is self-reported — bots routinely impersonate Chrome — which is why parsers check patterns in a careful order, and why production systems pair it with feature detection instead of trusting it alone.

Use Cases

  • Debugging: Reproduce bugs reported on specific browser and OS combinations
  • Log analysis: See which browsers and bots actually hit your site
  • Compatibility testing: Verify what UA strings your app will encounter
  • Privacy: Check what your own browser reveals to every website

Frequently Asked Questions

What is a user agent string?

A user agent string is a text identifier sent by your browser to websites you visit. It contains information about your browser, operating system, device type, and rendering engine. Websites use this information to optimize content delivery and ensure compatibility.

Can user agent strings be spoofed?

Yes, user agent strings can be easily modified or spoofed. Many browsers allow users to override their UA string, and bots often disguise themselves. For accurate browser detection, combine UA parsing with feature detection and other client-side checks.

Why does Edge appear as Chrome in some cases?

Microsoft Edge is built on Chromium and shares the same Blink rendering engine as Chrome. Our parser is designed to correctly identify Edge first before falling through to Chrome detection, ensuring accurate browser identification even with similar UA strings.