User-Agent Viewer

View and parse your browser's User-Agent string.

Your User Agent

About User-Agent Parsing & Client Identification

The User-Agent (UA) header is an HTTP request header string sent by web browsers, mobile applications, and web crawlers to identify the operating system, CPU architecture, browser engine, rendering capabilities, and software version to web servers.

Components of a Modern User-Agent String

A standard desktop Chrome User-Agent string looks like: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Mozilla Compatibility Token: Historical prefix retained by all modern browsers for backward compatibility with legacy web servers.
Platform & OS Version: Identifies the host environment (e.g., Windows 11, macOS, Linux, Android, iOS) and hardware architecture (x86_64, ARM64).
Rendering Engine: Identifies layout engines such as Blink / AppleWebKit (Chrome, Safari, Edge) or Gecko (Firefox).
Browser Brand & Build: The exact major and minor build version of the application.

Frequently Asked Questions (FAQ)

What are Client Hints (Sec-CH-UA)?

To improve user privacy and combat device fingerprinting, modern browsers are phasing out granular User-Agent strings in favor of User-Agent Client Hints (UA-CH), providing specific platform details only when explicitly requested by servers.

Can a User-Agent string be spoofed?

Yes. Any HTTP client, proxy, or browser extension can alter the User-Agent header, so it should never be relied upon for critical security decisions.