User Agent Parser
Free online user agent parser. No sign-up, no installation. Runs entirely in your browser.
What is a User Agent String?
A User Agent (UA) string is a text identifier that your web browser sends to every website you visit. It contains information about your browser, operating system, device type, and rendering engine. Web servers and applications use this information to detect your browser capabilities, optimize content delivery, and provide device-specific features.
For example, a typical UA string might look like: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36
How to Use This Tool
1. Auto-Detect: Click the “Auto-Detect Current” button to instantly parse your browser’s user agent string.
2. Custom Input: Paste any user agent string into the text area and click “Parse User Agent” to analyze it.
3. View Results: See detailed browser, OS, device type, and rendering engine information in an easy-to-read format.
4. History: Your last 5 parsed user agents are saved automatically for quick reference.
Common Use Cases
Web Development: Debug browser compatibility issues and test how your site renders on different platforms.
Analytics: Understand your website’s visitor demographics by analyzing user agent data from server logs.
Security: Identify suspicious or spoofed user agents that may indicate automated attacks or bot traffic.
Mobile Testing: Verify how your application detects and adapts to mobile, tablet, and desktop devices.
Frequently Asked Questions
What information can I extract from a user agent string?
You can extract the browser name and version, operating system and version, device type (desktop/mobile/tablet), rendering engine (Blink/Gecko/WebKit), and system architecture (32-bit/64-bit). This tool parses all this information automatically.
Is my user agent string stored or tracked?
No. This tool runs entirely in your browser. Your user agent string is never sent to any server. Only your recent history is stored in your browser’s local storage for convenience, and you can clear it anytime.
Why do some websites block certain user agents?
Websites may block or treat certain user agents differently for security, performance, or business reasons. Some block automated scrapers, old browsers with security vulnerabilities, or competitors. User agent filtering helps manage traffic and protect against abuse.
Can I change my user agent string?
Yes, modern browsers allow you to change your user agent string through developer tools or browser extensions. However, this doesn’t change your actual browser capabilities—it only changes what you tell websites you’re using. Websites can detect mismatches through feature detection.
What’s the difference between Blink, Gecko, and WebKit?
These are rendering engines that parse HTML/CSS and display web pages. Blink powers Chrome and Edge, Gecko powers Firefox, and WebKit powers Safari. Each engine has different JavaScript performance characteristics and CSS support levels.
Why is my user agent string so long?
Modern user agent strings are long due to historical reasons (for backward compatibility) and include many identifiers for different engines and frameworks. They also contain version numbers, OS details, and device capabilities. Much of this information is redundant today.