DevToolsHub

User-Agent Parser

See your current User-Agent string and a coarse parse of browser, OS, and device for support reproduction.

Treat results as hints—modern privacy changes reduce the precision of UA-based detection.

How to use

  1. Use my browser's UA — Fills the box with your current User-Agent and parses it.
  2. Paste a UA — Paste any User-Agent string to see the parsed browser, OS, and device type.
  3. Share URL — Copies a link with the current UA in the query string so others can see the same result.
  4. Copy raw — Copies the raw User-Agent string to the clipboard.

1User-Agent strings describe clients—imperfectly

Browsers advertise compatibility, platform, and device hints in a single header so servers can tailor responses, but the string is historical, sometimes misleading, and gradually frozen in modern privacy models.

Parsing still helps support engineers reproduce issues and helps analytics estimate mobile versus desktop traffic at a coarse level.

  • Never block features solely on User-Agent substrings; capability detection or progressive enhancement ages better.
  • Bots sometimes omit or spoof headers; treat parsed results as hints, not identity guarantees.

2Testing and QA

Copy a real User-Agent from a bug report into tests to verify your server returns the expected HTML variant or download filename.

When you rely on client hints headers instead, document the fallback path for browsers that do not send them yet.

3Privacy direction

Reduced User-Agent and Client Hints policies mean some fields will become coarser over time; plan analytics dashboards for less granularity.

Fingerprinting for marketing without consent creates regulatory risk—prefer explicit analytics events users understand.

4Support and analytics

Support tickets with the exact User-Agent help reproduce layout bugs on specific Safari or Chrome versions. Analytics use coarse buckets—do not over-fit product decisions to UA alone.

5Privacy trends

Browsers are freezing and reducing User-Agent detail. Plan feature detection and progressive enhancement instead of brittle UA sniffing for new features.

6Quick checklist for User-Agent usage

Use parsing for debugging and coarse analytics, not as the only gate for features. Plan for reduced granularity as browsers freeze legacy UA strings.

  • Prefer feature detection in client code when possible.
  • Log parsed results, not raw UA, when privacy policies require minimization.

Examples

Desktop Chrome (example)

Paste the exact string from browser devtools or a support ticket.

Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 Chrome/120.0.0.0 Safari/537.36

Mobile Safari hint

Parser extracts OS and device family for reproduction steps.

Mozilla/5.0 (iPhone; CPU iPhone OS 17_0 like Mac OS X) ...

Frequently asked questions

What is a User-Agent string?
A header browsers send describing client name, version, and platform. Servers and analytics use it for compatibility and coarse statistics.
Why does parsing show Unknown?
New browsers, bots, privacy-focused clients, or truncated strings may not match patterns. Treat results as hints.
Should I block users by User-Agent?
Fragile. Prefer authentication, rate limits, and capability detection. UA blocks are easy to spoof.
Is my User-Agent sent to your server?
Parsing runs in the browser from the string your browser provides. Share URL encodes a string you paste.
How is this different from Client Hints?
Client Hints are a newer, privacy-oriented mechanism. User-Agent strings remain common but are being reduced over time.

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