User Agent Parser
Parse and analyse any User Agent string. Identify browser, OS, device type, and rendering engine instantly.
Browser
Google Chrome 146.0.0.0
Operating System
macOS 10.15.7
Device Type
Desktop
Rendering Engine
WebKit/Blink
What Is a User Agent String?
Every time your browser requests a web page, it sends a User-Agent header that identifies itself. This string tells the server which browser you're using, which version, what operating system you're on, and sometimes which device. It's basically your browser's name tag.
The problem? User agent strings are notoriously messy. They've accumulated decades of compatibility hacks. Chrome's user agent contains "Safari" and "Mozilla" for historical reasons — every new browser pretends to be every older browser to avoid being blocked by servers that check for specific strings.
This parser untangles that mess. Paste a user agent string and instantly see the browser, version, operating system, device type, and rendering engine — without manually decoding the compatibility tokens.
Anatomy of a User Agent String
| Component | Example | What It Means |
|---|---|---|
| Mozilla/5.0 | Mozilla/5.0 | Compatibility token — almost every browser sends this regardless |
| Platform | (Windows NT 10.0; Win64; x64) | OS and architecture — Windows 10, 64-bit |
| Engine | AppleWebKit/537.36 | Rendering engine — Blink-based browsers use WebKit token |
| Browser | Chrome/120.0.6099.130 | Actual browser name and version |
| Compatibility | Safari/537.36 | Legacy token — Chrome includes Safari for compatibility |
What this means for you: Don't try to parse user agents with simple string matching. The tokens are misleading by design. Use a proper parser (like this tool) or a server-side library.
Common User Agents by Device Type
| Device | Key Identifier | Notes |
|---|---|---|
| Desktop Chrome | Chrome/xxx, no "Mobile" | Most common browser globally (~65% market share) |
| Mobile Chrome (Android) | Chrome/xxx Mobile, Linux; Android | Includes Android version and device model |
| Safari (Mac) | Version/xx Safari/xxx, Macintosh | Only browser without Chrome token |
| Safari (iPhone) | iPhone; CPU iPhone OS, Mobile Safari | All iOS browsers use WebKit engine underneath |
| Firefox | Gecko/xxx Firefox/xxx | Uses Gecko engine — only major non-WebKit/Blink browser |
| Googlebot | Googlebot/2.1 or Googlebot-Mobile | Google's web crawler — renders JavaScript |
| Bingbot | bingbot/2.0 | Microsoft's search crawler |
Why User Agents Matter
Analytics and Reporting
Your analytics platform parses user agents to show browser and device breakdowns. If your site gets 40% mobile traffic but your design only looks good on desktop, the user agent data tells you that.
Bot Detection
Legitimate crawlers identify themselves via user agent strings. Googlebot, Bingbot, and social media scrapers all have distinctive signatures. Parsing these helps you serve appropriate content.
Bug Reproduction
When a user reports a bug, their user agent tells you exactly which browser, version, and OS to test on. This cuts debugging time dramatically compared to "it doesn't work on my phone."
Content Negotiation
Some sites serve WebP images to Chrome and JPEG to older browsers. Others serve lighter pages to mobile devices. User agent detection (combined with feature detection) enables this.
Why User Agent Strings Are So Messy
Every modern browser's user agent string contains "Mozilla/5.0" — even Chrome, even Safari, even Edge. This is a legacy of the 1990s browser wars. When Netscape Navigator was dominant, websites checked for "Mozilla" to serve advanced features. Every browser since has included "Mozilla" in its UA string to avoid being served a degraded experience.
The result is absurd strings like Chrome's: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36. It claims to be Mozilla, uses WebKit, is "like Gecko", and mentions Safari — despite being Chrome on Windows. This is why parsing UA strings requires specialised tools rather than simple string matching.
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How to use this tool
Your current browser's user agent is auto-detected on page load
Paste any custom user agent string to analyse it
Click Parse to see the browser, OS, device type, and rendering engine
Common uses
- Identifying browser and OS from server log entries
- Debugging device-specific rendering issues from user bug reports
- Detecting bot traffic in website analytics
- Understanding which browsers your users actually use
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