https://github.com/ariya/uainfer

Infer the user agent from its User Agent string
https://github.com/ariya/uainfer

browser javascript nodejs user-agent user-agent-parser useragent

Last synced: 3 months ago
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Infer the user agent from its User Agent string

• Host: GitHub
• URL: https://github.com/ariya/uainfer
• Owner: ariya
• License: mit
• Created: 2018-10-06T03:44:52.000Z (almost 7 years ago)
• Default Branch: master
• Last Pushed: 2022-11-28T05:45:29.000Z (almost 3 years ago)
• Last Synced: 2025-06-04T00:05:09.462Z (4 months ago)
• Topics: browser, javascript, nodejs, user-agent, user-agent-parser, useragent
• Language: JavaScript
• Homepage: https://ariya.github.io/uainfer
• Size: 32.2 KB
• Stars: 22
• Watchers: 2
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

          
# uainfer

[![npm version](https://img.shields.io/npm/v/uainfer)](https://www.npmjs.com/package/uainfer)

[![npm bundle size (minified)](https://img.shields.io/bundlephobia/min/uainfer.svg)](https://bundlephobia.com/result?p=uainfer)

[![GitHub license](https://img.shields.io/github/license/ariya/tebakmasa)](https://github.com/ariya/uainfer/blob/master/LICENSE)

[![Tests](https://github.com/ariya/tebakmasa/workflows/Tests/badge.svg)](https://github.com/ariya/uainfer/actions)

This is a simple JavaScript library to infer the user agent from its claimed [User-Agent string](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/User-Agent). The objective of uainfer to provide a human-friendly answer to the inquiry _"What browser am I using?"_.

In the context of a web browser, the most common way to obtain the User-Agent string is from [the value](https://developer.mozilla.org/en-US/docs/Web/API/NavigatorID/userAgent) of `navigator.userAgent`. In the context of an HTTP server, it can be retrieved from the `User-Agent` header field in the HTTP request.

Example usage with Node.js REPL (or [![try it on RunKit](https://badge.runkitcdn.com/uainfer.svg)](https://npm.runkit.com/uainfer)):

```js

> uainfer = require('uainfer');

> claim = 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.2';

> ua = uainfer.analyze(claim);

> ua.toString()

'Internet Explorer 7 on Windows XP'

```

(To use this library in a front-end application, see this [JSFiddle demo](http://jsfiddle.net/5467k1tp/))

For browsers utilizing Chrome/Blink engine (Samsung Browser, Opera, Vivaldi, etc), the result can contain the corresponding equivalent version of Chrome:

```js

> console.log(ua)

UserAgent {

  browser:

   { name: 'Vivaldi',

     version: 1.96,

     fullVersion: '1.96.1147.52',

     chromeFamily: { version: 65, fullVersion: '65.0.3325.183' } },

  os: { name: 'Windows', version: '10' } }

```

Non-goals:

* Recognize every single web browsers and obscure user agents out there.

* Deduce other information such as CPU type, device, form factor, etc.

Design choices:

* For a better maintenance, avoid regular expressions.

* Always expand its small but fairly extensive test suite.

* Keep it tidy and lightweight ![npm bundle size (minified)](https://img.shields.io/bundlephobia/min/uainfer.svg)

This library is created and maintained by [@AriyaHidayat](https://twitter.com/AriyaHidayat).