ServiceWorkerGlobalScope: activate event

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

Bubbles No
Cancelable No
Interface ExtendableEvent
Event handler property ServiceWorkerGlobalScope.onactivate


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

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

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

You can also set up the event handler using the ServiceWorkerGlobalScope.onactivate property:

globalScope.onactivate = function(event) {


Specification Status Comment
Service Workers
The definition of 'activate' in that specification.
Working Draft

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
activate event
Chrome Full support 40Edge Full support ≤79Firefox Full support 44
Full support 44
Notes Extended Support Releases (ESR) before Firefox 78 ESR do not support service workers and the Push API.
IE No support NoOpera Full support 24Safari Full support 11.1WebView Android Full support 40Chrome Android Full support 40Firefox Android Full support 44Opera Android Full support 24Safari iOS Full support 11.3Samsung Internet Android Full support 4.0


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.

See also