Browser Telemetry Tool

What Is My User Agent? (Analyzer & Client Hints)

Instantly decode your browser's User-Agent string, operating system, rendering engine, CPU architecture, screen resolution, and crawler status.

Raw User Agent String

Test Preset UAs:

Browser & Version

Unknown Browser

Version undetected

Operating System

Unknown OS

Standard edition

Device Classification

Desktop

Standard End-User Device

Engine & CPU Arch

Unknown

Extracted Telemetry & Client Environment

Browser Family

Unknown Browser

Browser Major Version

N/A

Rendering Engine

Unknown

Platform / OS

Unknown OS

CPU Instruction Set

Unknown

Bot / Web Crawler

No (Human Browser)

Anatomy of a Modern User-Agent String

When a browser requests a webpage, it includes a string formatted like:
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36

Platform Token

(Macintosh; Intel Mac OS X 10_15_7) indicates the operating system and CPU architecture.

Rendering Engine

AppleWebKit/537.36 indicates the layout engine (Blink in Chromium is a fork of WebKit).

Compatibility Suffix

Safari/537.36 is included because early Safari browsers established WebKit compatibility patterns.

The Shift to User-Agent Client Hints (Sec-CH-UA)

To mitigate cross-site tracking and digital fingerprinting, Chromium has frozen granular OS versions in the legacy UA string (e.g. reporting Windows 10 for all Windows 11 devices). Instead, modern servers obtain precise information through explicit Client Hint HTTP headers:

Client Hint Header	Sample Value	Purpose
Sec-CH-UA	"Chromium";v="128", "Google Chrome";v="128"	Brand identity & major version
Sec-CH-UA-Mobile	?0 (Desktop) or ?1 (Mobile)	Binary device form-factor
Sec-CH-UA-Platform	"macOS" or "Windows"	Operating system name
Sec-CH-UA-Arch	"arm64" or "x86"	Underlying CPU instruction set (high entropy)

Frequently Asked Questions (FAQ)

This is a legacy artifact of the 1990s 'browser wars'. Netscape was codenamed Mozilla. When websites began serving advanced frames and styles exclusively to Netscape browsers, competing browsers (such as Microsoft Internet Explorer) added 'Mozilla' into their User-Agent headers to avoid being blocked. Today, almost every browser includes 'Mozilla/5.0' for historical compatibility.

Diagnostic Platform