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User Agent Parser

Parse any User-Agent string into browser, OS, and device. Free, and it runs entirely in your browser — nothing you enter is uploaded.

How to use the User Agent Parser

1. Your current browser's User-Agent is pre-filled. Edit it to parse any UA string.

2. The tool extracts browser name/version, OS, device type, and rendering engine.

3. Paste UA strings from your server logs or API requests to identify clients.

What is it?

The User-Agent string is sent by every HTTP client (browser, mobile app, API tool) in request headers. It identifies the client software — browser name, version, operating system, and rendering engine. Servers use it for analytics, content negotiation, and access control.

UA strings follow no strict standard and are notoriously quirky — Chrome includes "Safari" in its UA for historical compatibility reasons, and most browsers still include "Mozilla/5.0" from Netscape days. Parsing them reliably requires pattern matching against known patterns.

Example

User-Agent String (Chrome on macOS)
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36
↓
Parsed Result
Browser:  Chrome 120.0.0.0
OS:       macOS 10.15.7
Device:   Desktop
Engine:   Blink
Bot:      No

Your current browser UA is pre-filled. Paste any UA string from server logs or DevTools to parse it.

Benefits

Identify browser, OS, and device from any User-Agent string

Parse raw UA strings from HTTP request headers, server logs, or test requests into browser name, version, operating system, and device type.

Detect bot and crawler traffic from your server logs

The parser identifies Googlebot, Bingbot, and other crawlers by their User-Agent — distinguish bot traffic from real users in your analytics.

Debug browser-specific issues using the exact UA from a bug report

Paste the User-Agent from a bug report to confirm exactly which browser version and operating system caused the issue.

Verify your server-side UA detection logic classifies strings correctly

Test that your backend correctly identifies mobile, tablet, desktop, and bot clients before deploying UA-based branching logic.

Frequently asked questions

Why does Chrome's UA include 'Safari'?

For historical compatibility. Early sites blocked non-IE browsers. Browsers started spoofing each other's UAs so websites would allow them. Chrome's UA includes both Safari and Mozilla for the same reason.

Can I trust User-Agent for security decisions?

No. User-Agent can be spoofed by anyone. Never use it for authentication or authorization. It's fine for analytics and content optimization but not security.