User Agent Parser

Break a user agent string into browser, OS and device.

User agent string

Your own browser’s user agent is filled in automatically.

User agents are self-reported

The user agent is a header the client controls and can be changed freely. Never use it for security, access control or licensing. Prefer feature detection over browser sniffing.

What does User Agent Parser do?

Paste a user agent string to see the browser, version, rendering engine, operating system and device type it claims. Your own browser’s string is shown by default, along with the modern client hints that are replacing it.

How to Use User Agent Parser

1
Paste a user agent stringOr use your own, shown by default.
2
Read the breakdownBrowser, engine, OS and device.
3
Compare client hintsThe modern replacement for UA sniffing.

Key Features

Browser name, version and rendering engine
Operating system and version
Device type: desktop, mobile, tablet, console or bot
Your own user agent shown by default
Modern client hints listed alongside, where the browser exposes them
Bot and crawler detection

Frequently Asked Questions

Why are user agent strings so strange?

Historical compatibility. Every browser claimed to be Mozilla to pass 1990s sniffing, then claimed to be its competitors as new checks appeared. Modern Chrome still says "Mozilla/5.0 … like Gecko … Safari" for that reason.

Can a user agent be faked?

Trivially — it is a header the client sets. Never rely on it for security, access control or licensing. It is fine for analytics and for progressive enhancement decisions.

What are client hints?

A set of headers such as Sec-CH-UA that report browser and platform in a structured way, with high-entropy details only sent when a site requests them. They are the intended replacement for parsing the UA string.

Should I detect browsers by user agent?

Prefer feature detection — check whether the API you need exists. UA parsing breaks whenever a browser changes its string, which happens more often than you would expect.