ServiceWorkerGlobalScope: periodicsync event

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) => {};

Event type

Event properties

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") {

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

self.onperiodicsync = (event) => {
  // ...


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

Browser compatibility

BCD tables only load in the browser

See also