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ServiceWorkerGlobalScope: periodicsync event

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

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 periodicsync event of the ServiceWorkerGlobalScope interface is fired at timed intervals, specified when registering a PeriodicSyncManager.

This event is not cancelable and does not bubble.

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

addEventListener("periodicsync", (event) => { })

onperiodicsync = (event) => { }

Inherits properties from its ancestor, Event.

PeriodicSyncEvent.tag Read only: Returns the developer-defined identifier for this PeriodicSyncEvent. Multiple tags can be used by the web app to run different periodic tasks at different frequencies.

The following example shows how to respond to a periodic sync event in the service worker.

self.addEventListener("periodicsync", (event) => {
  if (event.tag === "get-latest-news") {
    event.waitUntil(fetchAndCacheLatestNews());
  }
});

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

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

Specification
Web Periodic Background Synchronization> # periodicsync-event>
Web Periodic Background Synchronization> # dom-serviceworkerglobalscope-onperiodicsync>

	Desktop					Mobile
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet	WebView Android	WebView on iOS
`periodicsync_event`	80	80	No	67	No	80	No	57	No	13.0	No	No