User Agent Parser
Paste a user-agent string to identify the client information it reports and review the limits of string-based detection.
How to Use User Agent Parser
- Copy the complete User-Agent request header without editing its tokens.
- Parse the string and review detected browser, engine, operating system, device, and version values.
- Treat the output as a compatibility hint and prefer feature detection or User-Agent Client Hints when the decision affects functionality.
Limits of User-Agent Detection
User-agent strings evolved for compatibility and often contain overlapping product tokens. Browsers can reduce version detail, mimic other clients, or allow users and automation to send arbitrary values.
Do not use parsing alone for security, identity, or entitlement decisions. Feature detection is more reliable for browser capabilities, and responsive design should not depend on a guessed device model.
User Agent Parser Example
A Chromium-based browser string can contain both `Chrome` and `Safari` tokens. Correct parsing uses token order and known relationships rather than treating every product name as an installed browser.
Frequently Asked Questions About User Agent Parser
Can a user-agent string be trusted?
No. Clients can modify or fabricate it, so it is descriptive input rather than proof of identity or capability.
Why does a Chrome user agent mention Safari?
Compatibility tokens remain in many strings so older sites serve usable content. Parsers must interpret the complete token pattern.
What are User-Agent Client Hints?
They are request and JavaScript APIs that provide selected client information in a more structured, privacy-aware form where supported.