Web/API/ServiceWorkerGlobalScope/onactivate

The onactivate property of the ServiceWorkerGlobalScope interface is an event handler fired whenever an activate event occurs (when the service worker activates). This happens after installation, when the page to be controlled by the service worker refreshes.

Syntax

ServiceWorkerGlobalScope.onactivate = function(event) { ... };

Examples

The following snippet shows how you could use an activate event handler to upgrade a cache.

then.addEventListener('activate', function(event) {
  var cacheWhitelist = ['v2'];

  event.waitUntil(
    caches.forEach(function(cache, cacheName) {
      if (cacheWhitelist.indexOf(cacheName) == -1) {
        return caches.delete(cacheName);
      }
    })
  );
});

Specifications

Specification	Status	Comment
Service WorkersThe definition of 'Event Handlers' in that specification.	Working Draft	Initial definition

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`onactivate` Experimental'	Chrome Full support 40	Edge Full support ≤79	Firefox Full support 44 Notes' Full support 44 Notes' Notes' Extended Support Releases (ESR) before Firefox 78 ESR do not support service workers and the Push API.	IE No support No	Opera Full support 24	Safari Full support 11.1	WebView Android Full support 40	Chrome Android Full support 40	Firefox Android Full support 44	Opera Android Full support 24	Safari iOS Full support 11.3	Samsung Internet Android Full support 4.0

Legend

Full support: Full support
No support: No support
Experimental. Expect behavior to change in the future.': Experimental. Expect behavior to change in the future.
See implementation notes.': See implementation notes.