User Agent Parser
Parse user agent strings to detect browser, engine, operating system, device type, and bot status. Supports all major browsers and platforms. Free, 100% in your browser.
Reference
What is a user agent string?
A user agent string is a text identifier sent by browsers and HTTP clients with every request via the User-Agent header. It typically contains the browser name and version, rendering engine, operating system, and device information. Originally simple (e.g., "Mosaic/0.9"), modern UA strings are notoriously complex due to decades of browser compatibility hacks — Chrome's UA string contains "Mozilla", "AppleWebKit", "Chrome", and "Safari" all at once.
User agent components
Browser — Chrome, Firefox, Safari, Edge, Opera, Samsung Internet, etc. Engine — WebKit (Chrome, Safari, Edge), Gecko (Firefox), Trident (old IE). OS — Windows NT version, macOS version, Android version, iOS version, Linux. Device — Desktop, Mobile, or Tablet (inferred from OS and device tokens). Bot — Googlebot, Bingbot, and other crawlers identify themselves in the UA string.
Common use cases
Web development — debug browser-specific issues by parsing the user agent. Analytics — understand your audience's browsers, devices, and OS distribution. A/B testing — segment experiments by device type or browser version. Bot detection — identify crawlers and automated traffic. Compatibility — check if a specific browser version supports the features you need.
Privacy
All parsing runs 100% in your browser. No data is sent to any server.