Create PWA (Create a Progressive Web Application)

Easily create a Progressive Web Application

About

create-pwa is a module for quick scaffolding and producing of progressive web applications.

create-pwa adds the minimum required boilerplate which your app requires in order to become a PWA.

create-pwa can be used with existing applications or can be the first thing one does when starting a new app.

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Dependencies

In order to use this module, you must have NodeJS installed and NPM or Yarn available.

You also need a bash shell installed and configured - default on OSX and linux or Git bash on Windows.

Install

# Using NPM:
npm i create-pwa --save-dev

# Using Yarn
yarn add create-pwa --dev

Arguments

icon: Specifies a relative path to the application icon. Should be a .png file.

This path is relative to the folder you are located in. It is recommended that the icon file is at least a 512x512 pixels square.

The icon argument is not required.

If the icon argument is not provided, the default icon is used.

launch: Specifies a relative path to the application launch (splash) screen. Should be a .png file.

This path is relative to the folder you are located in. It is recommended that the launch is at least 3200x3200 pixels square and the actual content (for example brand image) is located in the middle of the image in a square with dimensions up to 500x500 pixels.

The launch argument is not required.

If the launch argument is not provided, the default launch screen is used.

output: Specifies a relative path to the output directory.

This path is relative to the folder you are located in.

The output argument is not required.

If the output argument is not provided, the default value for it is empty string (the root of your project or the location of your package.json file).

Usage

If you want to use if from the command line, you should first install Create PWA globally:

npm i -g create-pwa

# or

yarn global add create-pwa

Then, navigate to your application's folder: Then run the install command (see above)

cd your/app/folder

create-pwa --icon="./icon.png" --launch="./launch.png"

You can also use create-pwa as a package.json script (in this case you don't need to install the package globally):

{
	"scripts": {
		"pwa": "create-pwa --icon=\"path/to/your/icon.png\" --launch=\"path/to/your/launch.png\""
	}
}

The above commands will generate:

a manifest.json and a service-worker.js files
several (8) png icons in the /icons/ folder in your app's root folder
several (19) favicons in the /favicons folder in your app's root folder
several (20) launch screen images in the launch-screen folder in your app's root folder
a config.xml file in your app's root folder - this file is required in Microsoft's browsers

You can edit the contents of the manifest.json and service-worker.js files.

Their default content is based on industry's best practices and is highly opinionated.

In order to create a customized experience for your users, feel advised to revise and edit the contents of the above files.

When the files(manifest.json and service-worker.js) are ready for production, you need to let the world know about them:

Feel adviced to edit the content of the <TileColor> tag in the config.xml file as it matches the color of your application's status bar on Chrome (found in the <meta name="color" /> tag);

Add the following to the head of your HTML file(s):

<link rel="manifest" href="manifest.json" />

You can read more about the Web App Manifest here.

Add the following snippet to your application's JavaScript bundle or place it in a script tag just before the closing </body> tag in your HTML file(s):

if ('serviceWorker' in navigator) {
	window.addEventListener('load', () => {
		navigator.serviceWorker.register('./service-worker.js').then(
			registration => {
				console.log(`ServiceWorker registration successful with scope: ${registration.scope}`);
			},
			error => {
				console.log(`ServiceWorker registration failed: ${error}`);
			}
		);
	});
}

The code above checks for service worker support and then registers a service worker located in the service-worker.js file in the root of the project.

You can read more about Service Workers here.

After that, add references to all icons which were generated by create-pwa:

Add the following favicons and meta tags in the head of your HTML file(s):

For more info about the favicons and meta tags below see here.

View favicons and meta tags

<!-- All Apple touch icons for iPad, iPhone, iPod -->
<link rel="apple-touch-icon" sizes="57x57" href="favicons/apple-touch-icon-57x57.png" />
<link rel="apple-touch-icon" sizes="60x60" href="favicons/apple-touch-icon-60x60.png" />
<link rel="apple-touch-icon" sizes="72x72" href="favicons/apple-touch-icon-72x72.png" />
<link rel="apple-touch-icon" sizes="76x76" href="favicons/apple-touch-icon-76x76.png" />
<link rel="apple-touch-icon" sizes="114x114" href="favicons/apple-touch-icon-114x114.png" />
<link rel="apple-touch-icon" sizes="120x120" href="favicons/apple-touch-icon-120x120.png" />
<link rel="apple-touch-icon" sizes="144x144" href="favicons/apple-touch-icon-144x144.png" />
<link rel="apple-touch-icon" sizes="152x152" href="favicons/apple-touch-icon-152x152.png" />

<!-- All favicon sizes - for all devices and browsers -->
<link rel="icon" type="image/png" href="favicons/favicon-196x196.png" sizes="196x196" />
<link rel="icon" type="image/png" href="favicons/favicon-96x96.png" sizes="96x96" />
<link rel="icon" type="image/png" href="favicons/favicon-32x32.png" sizes="32x32" />
<link rel="icon" type="image/png" href="favicons/favicon-16x16.png" sizes="16x16" />
<link rel="icon" type="image/png" href="favicons/favicon-128x128.png" sizes="128x128" />

<!-- A favicon with four different sizes -->
<link rel="shortcut icon" type="image/x-icon" href="favicons/favicon.ico" />

<!-- Application color for Microsoft Windows app tile and Android status bar -->
<meta name="theme-color" content="#edc22e" />
<meta name="msapplication-TileColor" content="#edc22e" />

<!-- Application name for Microsoft Windows app tile -->
<meta name="application-name" content="Create PWA" />

<!-- Application icons for Microsoft Windows app tile -->
<meta name="msapplication-TileImage" content="favicons/ms-tile-144x144.png" />
<meta name="msapplication-square70x70logo" content="favicons/ms-tile-70x70.png" />
<meta name="msapplication-square150x150logo" content="favicons/ms-tile-150x150.png" />
<meta name="msapplication-wide310x150logo" content="favicons/ms-tile-310x150.png" />
<meta name="msapplication-square310x310logo" content="favicons/ms-tile-310x310.png" />

<!-- Application config file for Microsoft browsers -->
<meta name="msapplication-config" content="config.xml" />

(Optional) Add the following launch screens in the head of your HTML file(s):

View launch screens

<!-- 12.9" iPad Pro Portrait -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-2048x2732.png"
	media="(device-width: 2048px) and (device-height: 2732px) and (orientation: portrait)"
/>

<!-- 12.9" iPad Pro Landscape -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-2732x2048.png"
	media="(device-width: 2732px) and (device-height: 2048px) and (orientation: landscape)"
/>

<!--  11" iPad Pro Portrait -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-1668x2388.png"
	media="(device-width: 1668px) and (device-height: 2388px) and (orientation: portrait)"
/>

<!--  11" iPad Pro Landscape -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-2388x1668.png"
	media="(device-width: 2388px) and (device-height: 1668px) and (orientation: landscape)"
/>

<!-- 10.5" iPad Pro Portrait -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-1668x2224.png"
	media="(device-width: 1668px) and (device-height: 2224px) and (orientation: portrait)"
/>

<!-- 10.5" iPad Pro Landscape -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-2224x1668.png"
	media="(device-width: 2224px) and (device-height: 1668px) and (orientation: landscape)"
/>

<!--  9.7" iPad Portrait -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-1536x2048.png"
	media="(device-width: 1536px) and (device-height: 2048px) and (orientation: portrait)"
/>

<!--  9.7" iPad Landscape -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-2048x1536.png"
	media="(device-width: 2048px) and (device-height: 1536px) and (orientation: landscape)"
/>

<!--7.9" iPad mini 4 Portrait -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-1536x2048.png"
	media="(device-width: 1536px) and (device-height: 2048px) and (orientation: portrait)"
/>

<!--7.9" iPad mini 4 Landscape -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-2048x1536.png"
	media="(device-width: 2048px and (device-height: 1536px) and (orientation: landscape)"
/>

<!--  iPhone XS Max Portrait -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-1242x2688.png"
	media="(device-width: 1242px and (device-height: 2688px) and (orientation: portrait)"
/>

<!--  iPhone XS Max Landscape -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-2688x1242.png"
	media="(device-width: 2688px) and (device-height: 142px) and (orientation: landscape)"
/>

<!--  iPhone XS Portrait -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-1125x2436.png"
	media="(device-width: 1125px) and (device-height: 236px) and (orientation: portrait)"
/>

<!--  iPhone XS Landscape -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-2436x1125.png"
	media="(device-width: 2436px) and (device-height: 1125px) and (orientation: landscape)"
/>

<!--  iPhone XR Portrait -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-828x1792.png"
	media="(device-width: 828px) and (device-height: 192px) and (orientation: portrait)"
/>

<!--  iPhone XR Landscape -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-1792x828.png"
	media="(device-width: 1792px) and (device-height: 28px) and (orientation: landscape)"
/>

<!--  iPhone X Portrait -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-1125x2436.png"
	media="(device-width: 1125px) and (device-height: 236px) and (orientation: portrait)"
/>

<!--  iPhone X Landscape -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-2436x1125.png"
	media="(device-width: 2436px and (device-height: 1125px) and (orientation: landscape)"
/>

<!--  iPhone 8 Plus Portrait -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-1242x2208.png"
	media="(device-width: 1242px and (device-height: 2208px) and (orientation: portrait)"
/>

<!--  iPhone 8 Plus Landscape -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-2208x1242.png"
	media="(device-width: 2208px) and (device-height: 1242px) and (orientation: landscape)"
/>

<!--  iPhone 8 Portrait -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-750x1334.png"
	media="(device-width: 750px) and (device-height: 134px) and (orientation: portrait)"
/>

<!--  iPhone 8 Landscape -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-1334x750.png"
	media="(device-width: 1334px and (device-height: 750px) and (orientation: landscape)"
/>

<!--  iPhone 7 Plus Portrait -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-1242x2208.png"
	media="(device-width: 1242px and (device-height: 2208px) and (orientation: portrait)"
/>

<!--  iPhone 7 Plus Landscape -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-2208x1242.png"
	media="(device-width: 2208px) and (device-height: 1242px) and (orientation: landscape)"
/>

<!--  iPhone 7 Portrait -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-750x1334.png"
	media="(device-width: 750px) and (device-height: 134px) and (orientation: portrait)"
/>

<!--  iPhone 7 Landscape -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-1334x750.png"
	media="(device-width: 1334px and (device-height: 750px) and (orientation: landscape)"
/>

<!--  iPhone 6s Plus Portrait -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-1242x2208.png"
	media="(device-width: 1242px and (device-height: 2208px) and (orientation: portrait)"
/>

<!--  iPhone 6s Plus Landscape -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-2208x1242.png"
	media="(device-width: 2208px) and (device-height: 1242px) and (orientation: landscape)"
/>

<!--  iPhone 6s Portrait -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-750x1334.png"
	media="(device-width: 750px) and (device-height: 134px) and (orientation: portrait)"
/>

<!--  iPhone 6s Landscape -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-1334x750.png"
	media="(device-width: 1334px) and (device-height: 50px) and (orientation: landscape)"
/>

<!--  iPhone SE Portrait -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-640x1136.png"
	media="(device-width: 640px) and (device-height: 136px) and (orientation: portrait)"
/>

<!--  iPhone SE Landscape -->
<link
	rel="apple-touch-startup-image"
	href="./launch-screens/launch-screen-1136x640.png"
	media="(device-width: 1136px) and (device-height: 640px) and (orientation: landscape)"
/>

In order to have the launch screens shown on an iOS device you also need to tell the device it is dealing with a web app:

<meta name="apple-mobile-web-app-capable" content="yes" /> <meta name="mobile-web-app-capable" content="yes" />

The formet works on Safari on all iOS devices. The latter works on Google Chrome on all iOS devices.

Android devices show splash screen based on the data provided in the manifest.json file: icons, name, etc.

(Optional) Add the following attribute to your html tag: manifest="<YOUR_APP_NAME>.appcache". It should look something like this:

<html lang="en" manifest="create-pwa.appcache">
	<!-- More awesome HTML code here -->
</html>

This will enable application cache and will cache all files listed in the .appcache file. Application cache is currently deprecated in most evergreen browsers and will probably be removed soon. This, however, does not mean that you can not use it in older browsers (for example IE 11).

You can read more about Application Cache here

More info

There is a lot information about Progressive Web Applications on the Internet. In order to comply with browser's requirements and pass the audits you need to check out and fulfill the PWA Checklist.

The entries listed in Baseline Progressive Web App Checklist are mandatory and without them your web app will not qualify as a PWA.

If you wish to test your web app's compliance, you can use the Chrome's built-in Lighthouse tool (found under the Audits tab in the Developer tools).

NodeJS API

You can generate each of the components above separately using the Create PWA API in NodeJS:

To create only an appcache file:

const { setAppCache } = require('create-pwa');
const appName = 'Your application name';
const distFolder = 'dist';

setAppCache(appName, distFolder);

The generated appcache file contains references to the application icons and application launch screens. You must have these already generated otherwise you must edit your appcache file and remove them.

To create only the application icons:

const { setIcons } = require('create-pwa');
const appIcon = require('fs').resolve(__dirname, './your_icon.png');
const distFolder = 'dist';

setIcons(appIcon, distFolder);

The generated icons are located in the /icons folder.

To create only the launch screens:

const { setLaunchScreens } = require('create-pwa');
const launchScreen = require('fs').resolve(__dirname, './your_launch_screen.png');
const distFolder = 'dist';

setLaunchScreens(launchScreen, distFolder);

The generated files are located in the /launch-screens folder.

To create only manifest file:

const { setManifest } = require('create-pwa');
const appName = 'Your application name';
const distFolder = 'dist';

setManifest(appName, distFolder);

The generated manifest.json file contains references to the application icons. You must have these already generated otherwise you must edit your manifest.json file and remove them.

To create only favicon files:

const { setFavicons } = require('create-pwa');
const appIcon = require('fs').resolve(__dirname, './your_icon.png');
const distFolder = 'dist';

setFavicons(appIcon, distFolder);

The generated files are located in the /favicons folder.

To create only service worker file:

const { setServiceWorker } = require('create-pwa');
const appName = 'Your application name';
const distFolder = 'dist';

setServiceWorker(appName, distFolder);

The generated service-worker.js file contains references to the application icons and application launch screens. You must have these already generated otherwise you must edit your service-worker.js file and remove them.