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Many browsers make it possible for you to enable and promote the installation of your Progressive Web App (PWA) directly within the user interface of your PWA. Installation (sometimes formerly referred to as Add to Home Screen), makes it easy for users to install your PWA on their mobile or desktop device. Installing a PWA adds it to a user's launcher, allowing it to be run like any other installed app.

In addition to the browser provided install experience, it's possible to provide your own custom install flow, directly within your app.

"Install App" button provided in the Spotify PWA

When considering whether to promote install, it's best to think about how users typically use your PWA. For example, if there's a set of users who use your PWA multiple times in a week, these users might benefit from the added convenience of launching your app from a smartphone homescreen or from the Start menu in a desktop operating system. Some productivity and entertainment applications also benefit from the extra screen real-estate created by removing the browser toolbars from the window in installed standalone or minimal-ui modes.

Promoting installation #

To indicate your Progressive Web App is installable, and to provide a custom in-app install flow:

Listen for the beforeinstallprompt event. Save the beforeinstallprompt event, so it can be used to trigger the install flow later. Alert the user that your PWA is installable, and provide a button or other element to start the in-app installation flow.

The beforeinstallprompt event, and the appinstalled event have been moved from the Web App Manifest spec to their own incubator. The Chrome team remains committed to supporting them, and has no plans to remove or deprecate support. web.dev continues to recommend using them to provide a customized install experience.

Listen for the beforeinstallprompt event #

If your Progressive Web App meets the required installation criteria, the browser fires a beforeinstallprompt event. Save a reference to the event, and update your user interface to indicate that the user can install your PWA. This is highlighted below.

let deferredPrompt ;



window . addEventListener ( 'beforeinstallprompt' , ( e ) => {



e . preventDefault ( ) ;



deferredPrompt = e ;



showInstallPromotion ( ) ;

} ) ;

There are many different patterns that you can use to notify the user your app can be installed and provide an in-app install flow, for example, a button in the header, an item in the navigation menu, or an item in your content feed.

In-app installation flow #

To provide in-app installation, provide a button or other interface element that a user can click to install your app. When the element is clicked, call prompt() on the saved beforeinstallprompt event (stored in the deferredPrompt variable). It shows the user a modal install dialog, asking them to confirm they want to install your PWA.

buttonInstall . addEventListener ( 'click' , ( e ) => {



hideMyInstallPromotion ( ) ;



deferredPrompt . prompt ( ) ;



deferredPrompt . userChoice . then ( ( choiceResult ) => {

if ( choiceResult . outcome === 'accepted' ) {

console . log ( 'User accepted the install prompt' ) ;

} else {

console . log ( 'User dismissed the install prompt' ) ;

}

} ) ;

} ) ;

The userChoice property is a promise that resolves with the user's choice. You can only call prompt() on the deferred event once. If the user dismisses it, you'll need to wait until the beforeinstallprompt event is fired again, typically immediately after the userChoice property has resolved.

Try it! Make a site installable using the beforeinstallprompt event.

Detect when the PWA was successfully installed #

You can use the userChoice property to determine if the user installed your app from within your user interface. But, if the user installs your PWA from the address bar or other browser component, userChoice won't help. Instead, you should listen for the appinstalled event. It is fired whenever your PWA is installed, no matter what mechanism is used to install your PWA.

window . addEventListener ( 'appinstalled' , ( evt ) => {



console . log ( 'INSTALL: Success' ) ;

} ) ;

Detect how the PWA was launched #

The CSS display-mode media query indicates how the PWA was launched, either in a browser tab, or as an installed PWA. This makes it possible to apply different styles depending on how the app was launched. For example, always hide the install button and provide a back button when launched as an installed PWA.

Track how the PWA was launched #

To track how users launch your PWA, use matchMedia() to test the display-mode media query. Safari on iOS doesn't support this yet, so you must check navigator.standalone , it returns a boolean indicating whether the browser is running in standalone mode.

window . addEventListener ( 'DOMContentLoaded' , ( ) => {

let displayMode = 'browser tab' ;

if ( navigator . standalone ) {

displayMode = 'standalone-ios' ;

}

if ( window . matchMedia ( '(display-mode: standalone)' ) . matches ) {

displayMode = 'standalone' ;

}



console . log ( 'DISPLAY_MODE_LAUNCH:' , displayMode ) ;

} ) ;

Track when the display mode changes #

To track if the user changes between standalone , and browser tab , listen for changes to the display-mode media query.

window . addEventListener ( 'DOMContentLoaded' , ( ) => {

window . matchMedia ( '(display-mode: standalone)' ) . addListener ( ( evt ) => {

let displayMode = 'browser tab' ;

if ( evt . matches ) {

displayMode = 'standalone' ;

}



console . log ( 'DISPLAY_MODE_CHANGED' , displayMode ) ;

} ) ;

} ) ;

To apply a different background color for a PWA when launched as an installed PWA, use conditional CSS:

@media all and ( display-mode : standalone ) {

body {

background-color : yellow ;

}

}

Updating your app's icon and name #

Chrome on Android #

On Android, when your PWA is launched, Chrome will check the currently installed manifest against the live manifest. If an update is required, it will be queued and updated once the device is plugged in and connected to Wi-Fi.

Chrome on Desktop #

On Desktop, the manifest is not automatically updated, but this is planned for a future update.