isMobile

A simple JS library that detects mobile devices in both the browser and NodeJS.

Why use isMobile?

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You might not need this library. In most cases, responsive design solves the problem of controlling how to render things across different screen sizes. I recommend a mobile first approach. But there are always edge cases. If you have an edge case, then this library might be for you.

My edge case at the time was redirecting users to a completely separate mobile site. I tried to keep this script small (currently ~1.3k bytes, minified) and simple, because it would need to execute in the , which is generally a bad idea, since JS blocks the downloading and rendering of all assets while it parses and executes. In the case of mobile redirection, I don't mind so much, because I want to start the redirect as soon as possible, before the device has a chance to start downloading and rendering other stuff. For non-mobile platforms, the script should execute fast, so the browser can quickly get back to downloading and rendering.

#### How it works in the browser

isMobile runs quickly during initial page load to detect mobile devices; it then creates a JavaScript object with the results.

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You might want to use this library to do server-side device detection to minimize the amount of bytes you send back to visitors. Or you have your own arbitrary use case.

#### How is works in NodeJS

You import and call the isMobile function, passing it a user agent string; it then returns a JavaScript object with the results.

Devices detected by isMobile

In a browser, the following properties of the global isMobile object will either be true or false. In Node, isMobile will be whatever you named the variable.

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- isMobile.apple.phone
- isMobile.apple.ipod
- isMobile.apple.tablet
- isMobile.apple.universal
- isMobile.apple.device (any mobile Apple device)

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- isMobile.android.phone
- isMobile.android.tablet
- isMobile.android.device (any mobile Android device; OkHttp user agents will match this)

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- isMobile.amazon.phone
- isMobile.amazon.tablet
- isMobile.amazon.device (any mobile Amazon Silk device)

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- isMobile.windows.phone
- isMobile.windows.tablet
- isMobile.windows.device (any mobile Windows device)

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- isMobile.other.blackberry_10
- isMobile.other.blackberry
- isMobile.other.opera (Opera Mini)
- isMobile.other.firefox
- isMobile.other.chrome
- isMobile.other.device (any "Other" device)

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- isMobile.any - any device matched
- isMobile.phone - any device in the 'phone' groups above
- isMobile.tablet - any device in the 'tablet' groups above

Usage

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#### Install

``bash
yarn add ismobilejs
`

or

`bash
npm install ismobilejs
`

#### Use

`ts
import isMobile from 'ismobilejs';
const userAgent = req.headers['user-agent'];
console.log(isMobile(userAgent).any);
`

Or pass in a window.navigator-shaped object that includes at least a userAgent property. To properly detect iPad on iOS 13, the object should also include the platform and maxTouchPoints properties.

`js
// this is just an example. window.navigator is readonly in the browser
window.navigator = {
...
userAgent: 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15) AppleWebKit/605.1.15 (KHTML, like Gecko)',
platform: 'MacIntel',
maxTouchPoints: 2,
..
}
`

`ts
import isMobile from 'ismobilejs';
console.log(isMobile(window.navigator).apple.tablet);
`

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A real-word example: I include the minified version of the script, inline, and at the top of the . Cellular connections tend to suck, so it would be wasteful overhead to open another connection, just to download ~1.3kb of JS:


`html










`

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Alternatively, you can include this library via jsDelivr CDN in a script tag:

Visit the isMobile jsDelivr page to get the most up-to-date URL pointing to the lastest version.

Building manually

After checking out the repo, install dependencies:

`bash
yarn install
`

Then build the library:

`bash
yarn build
`

Three versions of the library will be generated:

1. ./cjs/index.js - the CommonJS version of the library
2. ./esm/index.js - the ESModule version of the library
3. ./dist/isMobile.min.js - the browser version of the library

Additionally, types will be output to types.

Contributing

This library uses Spotify's web-scripts project to build, lint, test, format and release the this library.

You must use yarn commit rather than git commit` to commit files. This enforced commit messages to following a specific format and enables automation of release notes and version bump.