User-Agent Parser: Detect Browser, OS, Device
Paste a User-Agent header to parse browser name/version, OS, device type, and rendering engine instantly.
Try the free online tool mentioned in this guide:User-Agent Parser
What is a User-Agent string?
A User-Agent is an HTTP header that identifies the client (browser). Servers use it for analytics, compatibility, and debugging.
Example:
`
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36
`
This identifies: Windows 10, 64-bit, Chrome 120.
Why parse User-Agent?
- Analytics — track which browsers visit your site.
- Compatibility — serve alternate content for old browsers.
- Debugging — understand what user reported a bug from.
- Security — detect spoofed User-Agents or bots.
- Feature detection — enable/disable features based on browser capabilities.
User-Agent format breakdown
A typical UA contains:
- Product/Version — Mozilla/5.0 (mostly legacy).
- Operating System — Windows NT 10.0, Macintosh, Linux.
- Engine/Version — AppleWebKit, Gecko, Trident.
- Browser/Version — Chrome/120, Safari/537, Firefox/121.
- Device — Mobile, Tablet, or omitted for desktop.
Parsing workflow
1. Copy User-Agent from HTTP headers or request logs. 2. Paste into parser. 3. See breakdown — browser, version, OS, device. 4. Use for compatibility — test in that specific browser.
Frequently asked questions
Can User-Agent be spoofed?
Yes, any header can be faked. Don't rely on UA for security; use server-side checks.
Are User-Agent strings standardized?
No, each browser formats them differently. Parsing requires pattern matching and heuristics.
How do I get a User-Agent?
Browser DevTools (Network tab) show it in request headers. `navigator.userAgent` in JavaScript.