User Agent Parser

User Agent Parser

Parse any user agent string instantly. Detect browser, operating system, device type, and rendering engine — free, online, no installation needed.

Updated May 2026

Paste the full HTTP User-Agent header from any client or log file.

User Agent Parser Online — Detect Browser, OS & Device Free

Paste any user agent string and get instant, structured results. Our free User Agent Parser identifies the browser name and version, operating system, device type, and rendering engine in one click — no sign-up, no install, nothing to configure.

Whether you're debugging HTTP logs, building adaptive UIs, or analyzing bot traffic, this tool decodes raw UA strings into human-readable data in seconds.

How to Use the User Agent Parser

  1. Paste your UA string — Your current browser's user agent is auto-detected on load. Replace it with any string from a log file, HTTP header, or another device.
  2. Read the summary cards — Browser, OS, Device Type, and Engine are highlighted at a glance.
  3. Check the Technical Breakdown — Scroll down to see CPU architecture, browser vendor, core version, and language settings.
  4. Copy the results — Click "Copy" or press Shift+Enter to copy the full analysis to your clipboard.

What Is a User Agent String?

Every browser and HTTP client sends a user agent string with each request — it's part of the User-Agent HTTP header. The string identifies the software making the request: its name, version, operating system, and rendering engine.

A typical desktop Chrome UA looks like this:

Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36

The format evolved from the early web and now carries legacy tokens (Mozilla/5.0, like Gecko) that most browsers include for compatibility reasons, even if they don't use those engines. A parser cuts through this noise and extracts the meaningful signals.

What Information Can You Extract from a User Agent?

  • Browser name and version — Chrome 124, Firefox 125, Safari 17, Edge 124, etc.
  • Operating system — Windows 11, macOS Sonoma, Android 14, iOS 17, Linux, Chrome OS
  • Device type — Desktop, Mobile, Tablet, or Bot/Crawler
  • Rendering engine — Blink (Chrome/Edge), Gecko (Firefox), WebKit (Safari), Trident (IE)
  • CPU architecture — x86_64, ARM64, ARM, i686
  • Browser vendor — Google, Mozilla, Apple, Microsoft, Samsung

Common Use Cases

  • Debugging access logs: Server logs record raw UA strings. Paste them here to understand which browser or client made a request without reading the spec manually.
  • Detecting bots and crawlers: Googlebot, Bingbot, and other crawlers identify themselves in their UA strings. Use this tool to verify whether a string belongs to a legitimate bot.
  • Building adaptive UIs: When implementing progressive enhancement, testing how your UI behaves across different browser/OS combinations starts with knowing exactly what the UA string says.
  • Cross-browser QA testing: When a bug report includes a UA string from a user, parse it here to confirm the exact browser version and OS before trying to reproduce.
  • HTTP client fingerprinting: APIs and security tools often log UA strings. Analyzing them helps distinguish human traffic from automated requests.

Frequently Asked Questions

What is a user agent parser?

A user agent parser is a tool that reads a raw UA string sent by browsers and HTTP clients and breaks it down into structured fields: browser name, version, operating system, device type, and rendering engine. This tool does it entirely in your browser — nothing is sent to any server.

How does a user agent string look?

A typical Chrome on Windows UA string looks like: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36. The format includes legacy tokens for compatibility, which is why a parser is needed to extract the real browser and OS information.

How do I find my current user agent?

This tool detects your browser's user agent automatically when you open it. Alternatively, open any page, press F12 to open DevTools, go to the Console tab, and type navigator.userAgent. The full string will appear immediately.

Can I detect bots and crawlers with a user agent parser?

Yes. Well-known bots — Googlebot, Bingbot, Yandex, DuckDuckBot — include identifiable tokens in their UA strings. This parser flags device type as "Bot / Crawler" when those patterns are detected. Note that malicious bots sometimes spoof legitimate browser UAs to avoid detection.

What is the difference between user agent detection and feature detection?

User agent detection reads the UA string to infer the browser or device. Feature detection (preferred in modern web dev) checks whether a specific API or capability is available, regardless of the browser. For server-side routing, logging, and analytics, UA detection is still common and necessary.

Is this user agent parser free?

Yes, it is completely free, runs entirely in your browser, requires no account, and has no request limits. The parsing logic is 100% client-side.

Can I use a user agent parser in my application?

Yes. Popular libraries include ua-parser-js (JavaScript/Node), ua-parser (Python), and DeviceDetector (PHP, .NET, and more). This online tool lets you quickly test and validate strings without writing any code.

Resources

  • MDN — User-Agent header — Official documentation on the User-Agent HTTP header format and its history.
  • ua-parser-js on npm — The most popular JavaScript library for parsing UA strings programmatically in your own application.

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