What Is My User Agent? - Browser UA String Finder

View your browser's exact User Agent string. Analyze and understand the data your device sends to websites for identification.

Your User Agent String

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Understanding the User Agent String

A User Agent (UA) string is a line of text that identifies your browser, operating system, and device type to the web server. Every time you connect to a website, your browser sends this string as part of the HTTP header. Servers use this information to determine which version of a website to show you (e.g., mobile vs. desktop) or to analyze traffic statistics.

The User Agent string has evolved over decades and often contains legacy tokens for compatibility reasons. For example, almost every modern browser starts its User Agent with "Mozilla/5.0" to ensure compatibility with older web servers that expected Netscape Navigator.

Components of a User Agent

Mozilla Version: Almost always "5.0" in modern browsers.
Platform Information: Details about the OS (Windows NT 10.0, Macintosh, Linux, Android).
Rendering Engine: Identifies the engine used (AppleWebKit, Gecko, Trident).
Browser Name & Version: The specific browser (Chrome/120.0, Safari/605.1).
Device Info: Specific model information for mobile devices (Pixel 6, iPhone).

Why User Agents Matter for SEO

Search engine bots (crawlers) identify themselves using specific User Agent strings. Googlebot, Bingbot, and others have unique signatures. Webmasters can use the robots.txt file to include or exclude specific User Agents from crawling parts of their site. Spoofing a User Agent (pretending to be Googlebot) is a common tactic used by malicious scrapers, which is why verifying bot IPs is also important.

User Agent Switching and Spoofing

Developers frequently change ("spoof") their User Agent string to test how websites respond to different devices. Tools like Chrome DevTools allow you to simulate being an iPhone, iPad, or Android device by sending that device's specific User Agent string. This is essential for testing responsive design and mobile-specific features without needing the physical device.

The Future: Client Hints

Due to privacy concerns and the complexity of parsing User Agent strings, the web is slowly moving toward "Client Hints." This is a newer standard where the browser sends specific pieces of information (like screen width or reduced-data preference) in separate headers, rather than one long, messy string. However, the User Agent string will remain in use for the foreseeable future for backward compatibility.

Analyzing Your User Agent

This tool helps you see exactly what your browser is broadcasting. If you see unexpected information (like an old browser version or incorrect OS), it might indicate that your browser is outdated, or that a privacy extension is modifying your User Agent to protect your identity (a technique known as anti-fingerprinting).