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.

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

addEventListener("activate", (event) => {});

onactivate = (event) => {};

An ExtendableEvent. Inherits from Event.

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

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

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:

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

• install event
• ServiceWorkerGlobalScope
• Service Worker API