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How to Use User-Agent Parser: Complete Guide (2026)
Learn how to use user-agent parser free online — no signup, no download. Follow our step-by-step guide below.
What is User-Agent Parser?
Parse User-Agent strings to detect browser, operating system, device type, and rendering engine. Useful for debugging analytics discrepancies, implementing device-specific logic, and understanding your site's traffic. Also includes a UA string generator for testing.
- 100% browser-based — no data uploaded to servers
- Free to use — no signup required
- Instant results — no waiting
- Works on all devices — mobile, tablet, desktop
How to Use User-Agent Parser: Step-by-Step
- 1
Paste a User-Agent string
Type or paste a UA string (e.g., from your server logs or browser dev tools).
- 2
Parse
Click Parse. The browser, OS, device type, and engine are displayed.
- 3
Generate test UA (optional)
Generate UA strings for specific browsers/devices to test your site's responsive behavior.
Common Use Cases
Analytics debugging
Verify that your analytics tool is correctly identifying browser and OS from UA strings.
Device-specific logic
Test UA parsing logic in your code that serves different content to mobile vs. desktop.
Bot detection
Identify search engine bots (Googlebot, Bingbot) vs. real user traffic in server logs.
FAQ About User-Agent Parser
Are User-Agent strings reliable for device detection?
They can be spoofed. For reliable device detection, use a combination of UA parsing, screen size detection, and feature detection.
What is the difference between UA detection and feature detection?
UA detection checks the browser name/version string. Feature detection (modern approach) checks if a specific API exists (e.g., 'fetch' in window). Feature detection is more reliable.
Is this tool affiliated with any browser vendor?
No. This is an independent utility. UA parsing is based on the public UA string specification.
Ready to Try User-Agent Parser?
No signup. No download. 100% free.