What is a User-Agent string?

A User-Agent is an HTTP request header that identifies the client software making a request · typically the browser name and version, rendering engine, operating system and device. Servers use it for analytics, compatibility decisions and bot detection.

Can a User-Agent be spoofed?

Yes. The User-Agent is entirely client-controlled and trivial to forge. It should never be trusted for security decisions · only used as a hint. Malicious bots frequently impersonate real browsers.

Why does my browser report 'Mozilla'?

For historical compatibility reasons, almost every browser begins its User-Agent with 'Mozilla/5.0'. The real browser is identified later in the string by tokens such as Chrome, Safari, Firefox or Edg.

Is my data sent anywhere?

No. Parsing happens entirely in your browser with pattern matching. Nothing is uploaded.

User-Agent Parser

Paste a User-Agent string to detect the browser, version, operating system, device and bot signatures. Everything runs in your browser.

User-Agent string

Examples:

Parsed result

Results will appear here...

Related tools

How to use

Paste a UA string

Or click "Use my browser" to parse your own.

Read the breakdown

Browser, engine, OS, device and bot flags are detected instantly.

Investigate logs

Useful for triaging suspicious access logs and crawler traffic.

Frequently Asked Questions

An HTTP header identifying the client software · browser, version, engine, OS and device. Servers use it for analytics, compatibility and bot detection.

Yes · it is client-controlled and trivial to forge. Never trust it for security decisions. Malicious bots routinely impersonate real browsers.

For historical compatibility nearly every browser starts with 'Mozilla/5.0'. The real browser appears later via tokens like Chrome, Safari, Firefox or Edg.

No. Parsing happens entirely in your browser.

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