User Agent Parser

關於本工具

The User-Agent Parser extracts structured information from a User-Agent HTTP header string, identifying the browser name and version, operating system, device type, and rendering engine.

Parsing uses regular expression matching against known User-Agent patterns. It recognizes major browsers (Chrome, Firefox, Safari, Edge, Opera), operating systems (Windows, macOS, iOS, Android, Linux), and device types (Desktop, Mobile, Tablet).

使用方法

1. The tool auto-loads your current browser's User-Agent when opened.
2. To analyze a different UA string, uncheck 'Use my current browser's User-Agent'.
3. Paste any User-Agent string into the text area.
4. The breakdown table updates instantly with browser, OS, device type, and engine.

使用情境

Web developers test responsive behavior by checking what UA strings mobile devices send. Analytics engineers audit UA strings in server logs for bot detection. QA engineers simulate different browser environments for testing. Security engineers identify suspicious or spoofed User-Agent strings in HTTP traffic.

常見問題

• Can it detect all browsers? — It covers the most common browsers and operating systems using pattern matching. Rare or custom UA strings may show as Unknown.
• Is my User-Agent sent anywhere? — No. All parsing runs locally in the browser using JavaScript. Nothing is transmitted to a server.
• What is the rendering engine? — The engine is the browser's layout/JavaScript engine: Blink (Chrome/Edge/Opera), Gecko (Firefox), WebKit (Safari), or Trident (IE).