User Agent Parser – Parse User Online (Free Tool)
Free online User Agent Parser tool to parse and analyze User Agent strings. Extract browser name, version, operating system, and device information from UA strings. Perfect for web analytics and debugging browser compatibility issues.
Example Output
Concise breakdown matching what analytics and feature-flag tools would derive.
Browser: Chrome 120 — OS: Windows 10 — Device: Desktop — Engine: Blink
What is User Agent Parser?
User Agent Parser decodes the cryptic "Mozilla/5.0 (Windows NT 10.0...)" strings browsers send with every HTTP request. Extracts browser name + version, operating system, device class (desktop/tablet/mobile), and rendering engine — the fields most analytics and feature-detection tools care about.
Why use this tool?
- Open-and-go: bookmark the page once and never look for an alternative
- Instant results — no waiting on a server or upload progress bar
- Touch-friendly UI, fine on phones for on-the-go edits
- Works with very large inputs (multi-megabyte JSON, long regex patterns, big tables)
- No telemetry on the tokens, payloads, or code you paste in
How to use
- Click "Use my User Agent" to load your browser's UA, or paste any UA string
- See parsed fields: browser, version, OS, device type, engine
- Use the breakdown to verify analytics tracking or feature detection logic
Examples
Debug analytics
Find a suspicious UA in your logs, paste it here — instantly see if it's a real Chrome on Windows or a headless browser pretending.
Pre-flight feature detection
Confirm what fields a target browser exposes (e.g. Safari 16 on iOS) before relying on a specific UA pattern in conditional code.
Common use cases
- Reading server logs and grouping requests by device class
- Auditing UA-based feature detection in legacy code
- Spotting bot traffic with malformed or generic UAs
- QA testing: verifying spoofed UA strings parse as intended
Troubleshooting
- Reported browser is "Unknown" or vague.
- Modern browsers are reducing UA detail (UA Client Hints replacing the legacy string). Some new UAs lack version info on purpose — fall back to JS feature-detection in your app.
Frequently Asked Questions
A User Agent string is sent by browsers and applications to identify themselves to web servers. It contains information about the browser name, version, operating system, and sometimes device type.
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