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User Agent Parser

Parse and decode browser user-agent strings

Reviewed: AnyCalc Editorial|2026-07-19|Editorial policy|About

What this calculator does

The User-Agent string is an HTTP header sent by browsers and HTTP clients that identifies the application, operating system, device type, and rendering engine making the request. This tool parses any User-Agent string and breaks it down into its components: browser name and version, rendering engine, operating system, device type (desktop, mobile, tablet), and whether it belongs to a known bot or crawler. Developers use User-Agent analysis for browser-specific debugging, responsive design testing, bot detection, analytics filtering, and understanding their audience device distribution. The tool also displays your current browser User-Agent string.

Populated from your browser. Edit to test any UA string.

How to use

  1. 01
    View or paste a user agent
    See your current user-agent string or paste one to analyze.
  2. 02
    Review parsed details
    View the detected browser, OS, device type, and engine information.
  3. 03
    Copy the results
    Copy parsed details for debugging or analytics documentation.

User Agent Parser FAQ

Why are User-Agent strings so long and confusing?▾
User-Agent strings grew complex due to browser wars — browsers added tokens from competing browsers to avoid being blocked by websites that checked for specific browsers. Chrome identifies itself as Mozilla/Safari/Chrome for historical compatibility. This legacy makes parsing User-Agents non-trivial.
Is User-Agent reliable for browser detection?▾
User-Agent strings can be spoofed and are increasingly unreliable. Chrome is reducing User-Agent granularity via the User-Agent Reduction initiative. For feature detection, use JavaScript feature checks instead. For analytics, User-Agent Client Hints (UA-CH) API provides structured, privacy-conscious browser data.
How do I detect bots using User-Agent strings?▾
Major bots identify themselves: Googlebot, Bingbot, Slurp (Yahoo), and others include their name in the User-Agent. However, malicious bots often spoof legitimate browser User-Agents. Combine User-Agent analysis with IP reputation, request patterns, and reverse DNS verification for reliable bot detection.

Interpret carefully

Outputs are decision-support estimates, not a substitute for professional judgment.

  • Treating User Agent Parser output as a final professional diagnosis, quote, or legal determination
  • Entering approximate values when the result is sensitive to units or precision
  • Applying the FAQ answer (“Why are User-Agent strings so long and confusing?”) to a special case without checking assumptions

Next steps

  1. Double-check inputs against your source documents (labs, statements, specs, or notes).
  2. Confirm the method below matches your use case before you act on the number.
  3. For medical, financial, or production decisions, verify with a qualified professional.

Disclaimer: Results are informational only and do not constitute medical, financial, legal, or professional advice. Report issues: sublimernj@gmail.com

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