isMobile

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

Why use isMobile?

In the Browser

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 <head>, 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.

In NodeJS

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.

Apple devices

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

Android devices

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

Amazon Silk devices (also passes Android checks)

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

Windows devices

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

"Other" devices

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

Aggregate Groupings

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

Usage

Node.js

Install

yarn add ismobilejs

npm install ismobilejs

Use

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.

// 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,
  ..
}

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

Browser

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

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <script>
      // Minified version of isMobile included in the HTML since it's small
      (function () {var a={};var f=/iPhone/i,h=/iPod/i,i=/iPad/i,r=/\biOS-universal(?:.+)Mac\b/i,g=/\bAndroid(?:.+)Mobile\b/i,j=/Android/i,c=/(?:SD4930UR|\bSilk(?:.+)Mobile\b)/i,d=/Silk/i,b=/Windows Phone/i,k=/\bWindows(?:.+)ARM\b/i,m=/BlackBerry/i,n=/BB10/i,o=/Opera Mini/i,p=/\b(CriOS|Chrome)(?:.+)Mobile/i,q=/Mobile(?:.+)Firefox\b/i;function s(l){return function($){return $.test(l)}}function e(l){var $=(l=l||("undefined"!=typeof navigator?navigator.userAgent:"")).split("[FBAN");void 0!==$[1]&&(l=$[0]),void 0!==($=l.split("Twitter"))[1]&&(l=$[0]);var a=s(l),e={apple:{phone:a(f)&&!a(b),ipod:a(h),tablet:!a(f)&&a(i)&&!a(b),universal:a(r),device:(a(f)||a(h)||a(i))&&!a(b)},amazon:{phone:a(c),tablet:!a(c)&&a(d),device:a(c)||a(d)},android:{phone:!a(b)&&a(c)||!a(b)&&a(g),tablet:!a(b)&&!a(c)&&!a(g)&&(a(d)||a(j)),device:!a(b)&&(a(c)||a(d)||a(g)||a(j))||a(/\bokhttp\b/i)},windows:{phone:a(b),tablet:a(k),device:a(b)||a(k)},other:{blackberry:a(m),blackberry10:a(n),opera:a(o),firefox:a(q),chrome:a(p),device:a(m)||a(n)||a(o)||a(q)||a(p)},any:!1,phone:!1,tablet:!1};return e.any=e.apple.universal||e.apple.device||e.android.device||e.windows.device||e.other.device,e.phone=e.apple.phone||e.android.phone||e.windows.phone,e.tablet=e.apple.tablet||e.android.tablet||e.windows.tablet,e}a=e();if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=a}else if(typeof define==="function"&&define.amd){define(function(){return a})}else{this["isMobile"]=a}})();

      // My own arbitrary use of isMobile, as an example
      (function() {
        var MOBILE_SITE = '/mobile/index.html', // site to redirect to
          NO_REDIRECT = 'noredirect'; // cookie to prevent redirect

        // I only want to redirect iPhones, Android phones
        if (isMobile.apple.phone || isMobile.android.phone) {
          // Only redirect if the user didn't previously choose
          // to explicitly view the full site. This is validated
          // by checking if a "noredirect" cookie exists
          if (document.cookie.indexOf(NO_REDIRECT) === -1) {
            document.location = MOBILE_SITE;
          }
        }
      })();
    </script>
  </head>
  <body>
    <!-- imagine lots of html and content -->
  </body>
</html>

jsDelivr CDN

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

<script src="https://cdn.jsdelivr.net/npm/ismobilejs@1/dist/isMobile.min.js"></script>

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:

yarn install

Then build the library:

yarn build

Three versions of the library will be generated:

./cjs/index.js - the CommonJS version of the library
./esm/index.js - the ESModule version of the library
./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.

kaimallea / isMobile

readme