ServiceWorkerGlobalScope: install event

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since April 2018.

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

Note: This feature is only available in Service Workers.

The install event of the ServiceWorkerGlobalScope interface is fired when a ServiceWorkerRegistration acquires a new ServiceWorkerRegistration.installing worker.

This event is not cancelable and does not bubble.

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

js
addEventListener("install", (event) => { })

oninstall = (event) => { }

Event type

An ExtendableEvent. Inherits from Event.

Event ExtendableEvent

Event properties

Doesn't implement any specific properties, but inherits properties from its parent, Event.

Examples

The following snippet shows how an install event handler can be used to populate a cache with a number of responses, which the service worker can then use to serve assets offline:

js
self.addEventListener("install", (event) => {
  event.waitUntil(
    caches
      .open("v1")
      .then((cache) =>
        cache.addAll([
          "/",
          "/index.html",
          "/style.css",
          "/app.js",
          "/image-list.js",
          "/star-wars-logo.jpg",
          "/gallery/",
          "/gallery/bountyHunters.jpg",
          "/gallery/myLittleVader.jpg",
          "/gallery/snowTroopers.jpg",
        ]),
      ),
  );
});

You can also set up the event handler using the oninstall property:

js
self.oninstall = (event) => {
  // …
};

Specifications

Specification
Service Workers Nightly
# dom-serviceworkerglobalscope-oninstall

Browser compatibility

desktop mobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
install event
Chrome – Full support
Chrome 40 (Release date: 2015-01-21)
footnote Full support
Edge – Full support
Edge 17 (Release date: 2018-04-30)
footnote Full support
Firefox – Full support
Firefox 44 (Release date: 2016-01-26)
footnote
footnote The install event handler is called with an ExtendableEvent, not an InstallEvent.
Opera – Full support
Opera 24 (Release date: 2014-09-02)
footnote Full support
Safari – Full support
Safari 11.1 (Release date: 2018-04-12)
footnote
footnote Returns ExtendableEvent instead of InstallEvent.
Chrome Android – Full support
Chrome Android 40 (Release date: 2015-01-21)
footnote Full support
Firefox for Android – Full support
Firefox for Android 44 (Release date: 2016-01-26)
footnote
footnote The install event handler is called with an ExtendableEvent, not an InstallEvent.
Opera Android – Full support
Opera Android 24 (Release date: 2014-09-10)
footnote Full support
Safari on iOS – Full support
Safari on iOS 11.3 (Release date: 2018-03-29)
footnote
footnote Returns ExtendableEvent instead of InstallEvent.
Samsung Internet – Full support
Samsung Internet 4 (Release date: 2016-03-11)
footnote Full support
WebView Android – Full support
WebView Android 40 (Release date: 2015-01-21)
footnote Full support
WebView on iOS – No support
WebView on iOS
footnote No support

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support
No support
No support
See implementation notes.

See also