What is a user agent string?

A user agent (UA) string is a text identifier that browsers and HTTP clients send with every request. It tells the server which browser, rendering engine, operating system, and device the client is using. Servers can use this to serve optimized content or analytics.

Is my user agent data sent anywhere?

No. All parsing is done entirely in JavaScript in your browser. Your UA string is never transmitted to any server.

Why does my browser show as "Chrome" even though I use Edge?

Microsoft Edge (Chromium) includes "Chrome" in its UA string for compatibility reasons, along with "Edg/" to identify itself. The parser detects Edg/ first, so it correctly reports Edge rather than Chrome.

Can this detect every browser?

The parser covers the vast majority of common browsers including Chrome, Firefox, Safari, Edge, Opera, Samsung Internet, and many bots. Very obscure or custom UA strings may fall back to generic labels.

What device types are detected?

The parser classifies devices as Mobile, Tablet, Bot/Crawler, or Desktop based on keywords and patterns in the UA string.

Why do some UA strings show "Unknown" for the engine?

Unusual or minimal UA strings (like those from CLI tools or embedded agents) may omit standard engine tokens. The parser returns "Unknown" when no recognized engine token is present.

User Agent Parser

Name: User Agent Parser
Availability: InStock
Author: Nham Vu

Paste any user agent string to instantly extract browser, OS, device type, and rendering engine details.

User Agent String

Sample User Agents

Browser

Operating System

Device Type

Engine

Raw UA String

All Parsed Fields

Field	Value

Paste a user agent string above and click Parse UA, or click Use My UA to analyze your current browser.

Copied!

Summary

Paste any user agent string to instantly extract browser, OS, device type, and rendering engine details.

How it works

Paste a user agent string into the input field, or click "Use My UA" to load your browser's current user agent.
The parser applies a series of regex patterns to identify the browser, OS, device type, and rendering engine.
Results appear instantly in labeled cards below the input.
Use the copy button to copy the parsed UA string or individual field values.
Try the sample UAs to see how different browsers and devices are identified.

Use cases

Debug browser compatibility issues by inspecting the exact UA string a client sends.
Verify that your app correctly identifies mobile vs. desktop visitors.
Test UA detection logic during web development.
Identify bots and crawlers by parsing their UA strings.
Analyze server logs that contain raw user agent strings.
Check which rendering engine a specific browser version uses.
Confirm OS and browser versions for support tickets.
Validate that your custom UA string is well-formed before deployment.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu