User Agent Checker
Instantly detect your browser, operating system, device type, and rendering engine
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Test Any User Agent String
Paste a user agent string below to parse and inspect it
What is a User Agent?
A user agent is a string sent by your browser to every web server it connects to. It identifies your browser, version, operating system, and rendering engine.
Websites use this information to serve optimized content, apply browser-specific fixes, or redirect mobile users to a mobile-friendly version.
User Agent Format
A typical user agent looks like:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36Each token identifies the platform, engine, and browser, often including compatibility tokens for legacy support.
Common Use Cases
Browser Compatibility
Verify which browser and version is being used to debug rendering issues or test browser-specific CSS and JavaScript behavior.
Mobile Detection
Determine if a visitor is on a mobile device, tablet, or desktop to serve appropriate layouts and redirect strategies.
Bot Identification
Detect web crawlers, search engine bots, and scrapers by checking known bot signatures in the user agent string.
Web Scraping Debug
Test custom user agent strings used in web scraping or automated testing tools to see how they are interpreted.
Security Analysis
Inspect suspicious user agent strings from server logs to identify automated attacks, bots, or spoofed browsers.
QA Testing
Validate that your application correctly handles user agent overrides during cross-browser testing or device emulation.