User-Agent Parser
Decode any User-Agent string into browser, engine, OS, device type, CPU architecture, and bot detection. Compare two UAs side-by-side, copy individual fields, deep-link via #ua=.
How detection works & caveats
Detection uses a cascade of regex patterns inspired by ua-parser-js and MDN guidance. Browser sniffing is inherently fragile — User-Agents are intentionally misleading (Chrome pretends to be Safari, Safari pretends to be Mozilla, Edge pretends to be Chrome…).
Engine is more reliable than browser name. Device model is only exposed by iOS Safari and some Android browsers. CPU arch is best-effort from x64 / WOW64 / ARM hints.
For new code, prefer feature detection (navigator.userAgentData Client Hints) over UA sniffing.
About this tool
User-Agent Parser decodes the User-Agent string your browser or any HTTP client sends, identifying the browser name and version, rendering engine (Blink, WebKit, Gecko, Trident), operating system, device type (desktop, mobile, tablet, TV, console), CPU architecture, and whether the request is a known bot or crawler.
Example: Mozilla/5.0 (iPhone; CPU iPhone OS 17_4 like Mac OS X) … Version/17.4 Mobile/15E148 Safari/604.1 parses to Safari 17.4 · iOS 17.4 · Mobile · Apple · ARM64. A Googlebot string is flagged with a dedicated bot banner.
Common uses: debugging why a feature works on one device but not another, checking whether server-side UA detection will classify a request correctly, identifying bot traffic in access logs, or verifying your own browser's UA before spoofing it for testing.
FAQ
Why does Chrome say "Mozilla" and "Safari" in its User-Agent? ›
Historical compatibility. In the early 2000s sites checked for "Mozilla" and "Safari" to serve modern content, so Chrome, Edge, and Firefox all include those tokens to this day. The parser checks for browser-specific tokens like Chrome/, Edg/, and OPR/ in the right order to identify the real browser.
Can the tool tell Windows 10 from Windows 11? ›
Not reliably — both report "Windows NT 10.0" in the User-Agent string. The parser shows Windows 11/10 with a warning. Client Hints (navigator.userAgentData) can distinguish them in modern browsers, but plain UA sniffing cannot.
How does bot detection work? ›
The tool matches against a curated list of over 50 known crawlers and HTTP libraries — Googlebot, GPTBot, Facebook, Twitter, Slack, Ahrefs, Semrush, monitoring services like UptimeRobot and Pingdom, and HTTP clients like curl, wget, okhttp, and Python-urllib. If a match is found, a banner labels the request as a bot.
Is User-Agent sniffing reliable? ›
It is inherently fragile because User-Agents are designed to be backwards-compatible and intentionally misleading. The parsing engine field is more stable than browser name. For new code, prefer feature detection or navigator.userAgentData Client Hints over string parsing.