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

The ServiceWorkerRegistration interface of the ServiceWorker API represents the service worker registration. You register a service worker to control one or more pages that share the same origin.

The lifetime of a service worker registration is beyond that of the ServiceWorkerRegistration objects that represent them within the lifetime of their corresponding service worker clients. The browser maintains a persistent list of active ServiceWorkerRegistration objects.

Note: This feature is available in Web Workers.


Also implements properties from its parent interface, EventTarget.

ServiceWorkerRegistration.scope (en-US) Read only
Returns a unique identifier for a service worker registration. This must be on the same origin as the document that registers the ServiceWorker.
ServiceWorkerRegistration.installing Read only
Returns a service worker whose state is installing. This is initially set to null.
ServiceWorkerRegistration.waiting (en-US) Read only
Returns a service worker whose state is waiting. This is initially set to null. Read only
Returns a service worker whose state is either activating or activated. This is initially set to null. An active worker will control a ServiceWorkerClient (en-US) if the client's URL falls within the scope of the registration (the scope option set when ServiceWorkerContainer.register (en-US) is first called.)
ServiceWorkerRegistration.navigationPreload Read only
Returns the instance of NavigationPreloadManager (en-US) associated with the current service worker registration.
ServiceWorkerRegistration.pushManager (en-US) Read only
Returns a reference to the PushManager interface for managing push subscriptions including subscribing, getting an active subscription, and accessing push permission status.
ServiceWorkerRegistration.sync (en-US)  Read only  
Returns a reference to the SyncManager (en-US) interface, which manages background synchronization processes.

Unimplemented properties

serviceWorkerRegistration.periodicSync (en-US) Read only
Returns a reference to the PeriodicSyncManager (en-US) interface, which manages periodic background synchronization processes. This was mentioned as an idea in the SW explainer at some point, but as yet has not been implemented anywhere.

Event handlers

ServiceWorkerRegistration.onupdatefound (en-US) Read only
An EventListener property called whenever an event of type updatefound is fired; it is fired any time the ServiceWorkerRegistration.installing property acquires a new service worker.


Also implements methods from its parent interface, EventTarget.

ServiceWorkerRegistration.getNotifications() (en-US)
Returns a Promise that resolves to an array of Notification objects.
ServiceWorkerRegistration.showNotification() (en-US)
Displays the notification with the requested title.
ServiceWorkerRegistration.update() (en-US)
Checks the server for an updated version of the service worker without consulting caches.
ServiceWorkerRegistration.unregister() (en-US)
Unregisters the service worker registration and returns a Promise. The service worker will finish any ongoing operations before it is unregistered.


In this example, the code first checks whether the browser supports service workers and if so registers one. Next, it adds and updatefound event in which it uses the service worker registration to listen for further changes to the service worker's state. If the service worker hasn't changed since the last time it was registered, than the updatefound event will not be fired.

if ('serviceWorker' in navigator) {
  .then(function(registration) {
    registration.addEventListener('updatefound', function() {
      // If updatefound is fired, it means that there's
      // a new service worker being installed.
      var installingWorker = registration.installing;
      console.log('A new service worker is being installed:',

      // You can listen for changes to the installing service worker's
      // state via installingWorker.onstatechange
  .catch(function(error) {
    console.log('Service worker registration failed:', error);
} else {
  console.log('Service workers are not supported.');


Specification Status Comment
Service Workers
The definition of 'ServiceWorkerRegistration' in that specification.
Working Draft Initial definition.
Push API
The definition of 'PushManager' in that specification.
Working Draft Adds the pushManager property.
Notifications API Living Standard Adds the showNotification() (en-US) method and the getNotifications() (en-US) method.
Web Background Synchronization Living Standard Adds the sync (en-US) property.

Browser compatibility

BCD tables only load in the browser

See also