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.

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.
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.
// Initialize deferredPrompt for use later to show browser install prompt.
let deferredPrompt;
window.addEventListener('beforeinstallprompt', (e) => {
// Prevent the mini-infobar from appearing on mobile
e.preventDefault();
// Stash the event so it can be triggered later.
deferredPrompt = e;
// Update UI notify the user they can install the PWA
showInstallPromotion();
// Optionally, send analytics event that PWA install promo was shown.
console.log(`'beforeinstallprompt' event was fired.`);
});
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', async () => {
// Hide the app provided install promotion
hideInstallPromotion();
// Show the install prompt
deferredPrompt.prompt();
// Wait for the user to respond to the prompt
const { outcome } = await deferredPrompt.userChoice;
// Optionally, send analytics event with outcome of user choice
console.log(`User response to the install prompt: ${outcome}`);
// We've used the prompt, and can't use it again, throw it away
deferredPrompt = null;
});
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.
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', () => {
// Hide the app-provided install promotion
hideInstallPromotion();
// Clear the deferredPrompt so it can be garbage collected
deferredPrompt = null;
// Optionally, send analytics event to indicate successful install
console.log('PWA was installed');
});
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.
function getPWADisplayMode() {
const isStandalone = window.matchMedia('(display-mode: standalone)').matches;
if (document.referrer.startsWith('android-app://')) {
return 'twa';
} else if (navigator.standalone || isStandalone) {
return 'standalone';
}
return 'browser';
}
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.matchMedia('(display-mode: standalone)').addEventListener('change', (evt) => {
let displayMode = 'browser';
if (evt.matches) {
displayMode = 'standalone';
}
// Log display mode change to analytics
console.log('DISPLAY_MODE_CHANGED', displayMode);
});
Update UI based on the current display mode
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
What if you need to update your app name, or provide new icons? Check out How Chrome handles updates to the web app manifest to see when and how are those changes are reflected in Chrome.