User Agent Detection
See your complete browser user agent string and understand what it reveals.
A user agent is a text string your browser sends to every website you visit. It contains your browser name, version, operating system, and device type. Websites use it to serve compatible content and track browser usage statistics.
Every time you visit a website, your browser sends a user agent string in the HTTP headers. This string contains information about your browser, rendering engine, and operating system.
Websites use this information to serve compatible content, track browser statistics, and sometimes to identify bots. However, user agents can be modified, so they shouldn't be relied upon for security.
Common components: the Mozilla/5.0 prefix (historical compatibility), a platform token carrying operating system information, an engine token (Gecko, WebKit, Blink), and a browser token with name and version.
We read navigator.userAgent — the same string your browser puts in every HTTP request's User-Agent header. To build the parsed breakdown, we run standard regex patterns for the major engines and browser families.
User-agent parsing is inherently fuzzy: modern browsers include multiple browser tokens for compatibility. Client Hints (Sec-CH-UA) are gradually replacing this, but the classic string is still what most servers rely on.
Bots and scrapers commonly fake this string. Mismatches between the user agent and other signals — screen size, timezone, WebGL renderer — are the classic way to catch them.
Need to see the exact identifier your browser sends to websites? This free lookup tool displays your complete user agent string — the text header revealing browser type, version, platform, and rendering engine. Essential for web development, IT troubleshooting, and understanding digital fingerprinting.
Every HTTP request includes this identifier in headers. Servers use it to serve compatible content, optimize rendering, track usage patterns, and detect automated bots. Our tool shows exactly what websites receive when you connect — the same data accessible to any site you visit.
Strings typically contain several components: Mozilla/5.0 prefix (historical compatibility), platform information, rendering engine (WebKit, Gecko, Blink), and specific application name with version. Modern agents include tokens from multiple browsers for maximum site compatibility — explaining why Chrome strings mention Safari and Mozilla.
Developers use agent detection for cross-browser testing and responsive debugging. IT professionals request these strings when diagnosing browser-specific issues. Privacy researchers analyze them to understand fingerprinting techniques that track users across sites without cookies.
Modification is possible through developer tools or extensions — useful for testing mobile layouts on desktop, bypassing browser-based restrictions, or reducing fingerprint uniqueness. However, custom strings may break sites relying on accurate detection for compatibility features.
This page displays the complete string with one-click copy plus a parsed breakdown showing detected browser, OS, and device classification. Works across all platforms without registration. No files or system settings are accessed during detection.
A user agent string is text your browser sends to websites that identifies your browser, its version, and your operating system. It helps websites deliver compatible content for your specific setup.
Yes, most browsers allow you to modify your user agent through developer tools or extensions. This is often used for testing how websites appear on different browsers or devices, or for privacy purposes.
For historical reasons, browsers often include other browser names in their user agent strings for compatibility. For example, Chrome includes 'Safari' and 'Mozilla' because early websites used these strings to detect browser capabilities.