Practical guide
How to use the user-agent parser
The User-Agent parser separates a browser identification string into recognizable device, operating-system and browser fields. It is useful for log analysis, but modern user agents are reduced, spoofable and not a reliable identity signal.
Good reasons to use it
- Turn a raw access-log user agent into readable components.
- Compare a reported client with a browser compatibility issue.
- Identify obvious bots or libraries before deeper verification.
A reliable workflow
- Paste the complete user-agent string.
- Review the parsed family, version, operating system and device.
- Corroborate the result with client hints, behavior and verified-bot checks.
How to interpret the result
The parser infers from tokens supplied by the client. Browsers may freeze or reduce these tokens, privacy tools may alter them, and malicious clients can claim any value.
Frequently asked questions
Can a user agent identify a person?
No. It describes software claims and can be shared or changed by many users.
How do I verify Googlebot?
Use Google’s documented reverse and forward DNS verification or published IP ranges, not the user-agent text alone.