The 'useragent' npm package is used to parse and identify user agent strings. It helps in detecting the browser, version, operating system, and device type from a given user agent string.

What are useragent's main functionalities?

Parsing User Agent Strings

This feature allows you to parse a user agent string and get a readable format of the browser, version, and operating system.

const useragent = require('useragent');
const agent = useragent.parse('Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3');
console.log(agent.toString());

Detecting Browser

This feature allows you to detect the browser family from a user agent string.

const useragent = require('useragent');
const agent = useragent.parse('Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3');
console.log(agent.family);

Detecting Operating System

This feature allows you to detect the operating system from a user agent string.

const useragent = require('useragent');
const agent = useragent.parse('Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3');
console.log(agent.os.toString());

Detecting Device Type

This feature allows you to detect the device type from a user agent string.

const useragent = require('useragent');
const agent = useragent.parse('Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3');
console.log(agent.device.toString());

Other packages similar to useragent

Readme

Source

#node-useragent

A user agent string parser for Node.js. Based on the Browserscope.org UA parser so we can actually get accurate version numbers of the browsers instead parsing out the render engine version numbers.

Installation

Using the npm package manager

npm install useragent

Through git

git clone git://github.com/3rd-Eden/node-useragent.git

What can it do

I could write a whole story about it, but just fire check out the example node example.js and navigate to http://127.0.0.1:8000/ In your browser you will see the following ( if you are using Chrome like I did ):

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_4; en-US) AppleWebKit/534.10 (KHTML, like Gecko) Chrome/8.0.559.0 Safari/534.10

userAgent.is {"version":"534.10","webkit":true,"opera":false,"ie":false,"firefox":true,"safari":true,"mobile_safari":false} userAgent.parser {"family":"Chrome","V1":"8","V2":"0","V3":"559","match":"Chrome/8.0.559","os":{"match":"OS X 10_6_4","family":"OS X","V1":"10","V2":"6","V3":"4"}} userAgent response.pretty Chrome 8.0.559 userAgent response.prettyOs OS X 10.6.4

As you can see in the example above, there are different ways of parsing the user-agent string. Usually using .browser() would be enough to do some low level user-agent targeting. It parses it in a way that most client side libraries would parse the user-agent. This is however not that accurate. As you can see in the in the output above the .browser() tell us the version if 533.8, but the real version of the browser is 4.0.4.

The .parser() generates a user_agent object, this contains the:

Browser / Family name.
Version number information ( V1.V2.V3 ).
Os object, contains the Family and version numbers.
Matched string of the user agent.
pretty(), a method that prints out the browser in pretty string.
prettyOs, a method that prints out the operating system in a pretty string.

Keywords

FAQs

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Last updated on 29 Dec 2010

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