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ServiceWorkerGlobalScope: activate event

The activate event of the ServiceWorkerGlobalScope interface is fired when a ServiceWorkerRegistration acquires a new ServiceWorkerRegistration.active 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("activate", (event) => {});

onactivate = (event) => {};

Event type

Event properties

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

Examples

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

js

self.addEventListener("activate", (event) => {
  const cacheAllowlist = ["v2"];

  event.waitUntil(
    caches.forEach((cache, cacheName) => {
      if (!cacheAllowlist.includes(cacheName)) {
        return caches.delete(cacheName);
      }
    }),
  );
});

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

js

self.onactivate = (event) => {
  // ...
};

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
activate_event 40 17 44 No 24 11.1 40 40 44 24 11.3 4.0

See also

© 2005–2023 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/ServiceWorkerGlobalScope/activate_event