User-Agent parser

Client

Paste a full User-Agent header to see structured browser, engine, OS, and device fields—no network request.

User-Agent strings in analytics and logs

Servers and browsers send a User-Agent string to describe the client stack. Modern browsers may reduce detail for privacy; bots and API clients often use fixed signatures. Use parsed fields for triage and routing hints, not as proof of identity.

Correlate HTTP errors with the status code list and headers reference when you chase differences between mobile and desktop traffic.

User-Agent

?

Parsed locally—paste a UA from server logs or DevTools. Redact internal build tokens if you share screenshots.

Browser
Chrome (120.0.0.0)
Engine
Blink (120.0.0.0)
OS
macOS (10.15.7)
Device
Macintosh · Apple
CPU

Nearby workflows on Toolcore

  • HTTP headerswhen User-Agent sits beside forwarded or auth headers.
  • MIME typesto map file types clients claim to accept.

Common use cases

  • Decode User-Agent strings from server logs to see browser family, OS, and device class.
  • Compare what your app thinks the client is versus what DevTools reports.
  • Sanity-check bot or crawler signatures when filtering traffic.

Common mistakes to avoid

  • Trusting User-Agent for security decisions alone

    Clients can spoof the header. Use it for analytics and hints, not for authentication.

  • Expecting stable strings forever

    Browsers freeze or reduce detail over time. Log raw strings but avoid brittle substring checks.

  • Confusing engine and browser brands

    Many browsers share an engine. Read both engine and product fields when diagnosing issues.

FAQ

Is the User-Agent sent to Toolcore?

No. Parsing happens locally after you paste.

Why does my browser show a simplified UA?

Modern browsers may send a reduced string for privacy. Your logs may differ from older documentation.

Can I get geolocation from the UA?

Not reliably—use explicit location APIs or server-side geo where appropriate.

Common search terms

Phrases people search for that match this tool. See the full long-tail keyword index.

  • user agent parser online
  • parse browser os from ua string

Related utilities you can open in another tab—mostly client-side.