ServiceWorkerRegistration

Baseline Widely available *

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨April 2018⁩.

* Some parts of this feature may have varying levels of support.

Secure context: This feature is available only insecure contexts (HTTPS), in some or allsupporting browsers.

Note: This feature is available inWeb Workers.

TheServiceWorkerRegistration interface of theService Worker 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 theServiceWorkerRegistration objects that represent them within the lifetime of their corresponding service worker clients. The browser maintains a persistent list of activeServiceWorkerRegistration objects.

Instance properties

Also inherits properties from its parent interface,EventTarget.

ServiceWorkerRegistration.activeRead only: Returns a service worker whose state isactivating oractivated. This is initially set tonull. An active worker will control aClient if the client's URL falls within the scope of the registration (thescope option set whenServiceWorkerContainer.register is first called.)
ServiceWorkerRegistration.backgroundFetchRead onlyExperimental: Returns a reference to a BackgroundFetchManager object, which manages background fetch operations.
ServiceWorkerRegistration.cookiesRead only: Returns a reference to theCookieStoreManager interface, which allows subscribe and unsubscribe to cookie change events.
ServiceWorkerRegistration.indexRead onlyExperimental: Returns a reference to the ContentIndex interface, for managing indexed content for offline viewing.
ServiceWorkerRegistration.installingRead only: Returns a service worker whose state isinstalling. This is initially set tonull.
ServiceWorkerRegistration.navigationPreloadRead only: Returns the instance ofNavigationPreloadManager associated with the current service worker registration.
ServiceWorkerRegistration.paymentManagerRead onlyExperimental: Returns a payment app's PaymentManager instance, which is used to manage various payment app functionality.
ServiceWorkerRegistration.periodicSyncRead onlyExperimental: Returns a reference to the PeriodicSyncManager interface, which allows for registering of tasks to run at specific intervals.
ServiceWorkerRegistration.pushManagerRead only: Returns a reference to thePushManager interface for managing push subscriptions including subscribing, getting an active subscription, and accessing push permission status.
ServiceWorkerRegistration.scopeRead only: Returns a string representing a URL that defines a service worker's registration scope; that is, the range of URLs the service worker can control.
ServiceWorkerRegistration.syncRead only: Returns a reference to theSyncManager interface, which manages background synchronization processes.
ServiceWorkerRegistration.updateViaCacheRead only: Returns the value of the setting used to determine the circumstances in which the browser will consult the HTTP cache when it tries to update the service worker or any scripts that are imported viaimportScripts(). It can be one of the following:imports,all, ornone.
ServiceWorkerRegistration.waitingRead only: Returns a service worker whose state isinstalled. This is initially set tonull.

Instance methods

Also inherits methods from its parent interface,EventTarget.

ServiceWorkerRegistration.getNotifications(): Returns a list of the notifications in the order that they were created from the current origin via the current service worker registration.
ServiceWorkerRegistration.showNotification(): Displays the notification with the requested title.
ServiceWorkerRegistration.unregister(): Unregisters the service worker registration and returns aPromise. The service worker will finish any ongoing operations before it is unregistered.
ServiceWorkerRegistration.update(): Checks the server for an updated version of the service worker without consulting caches.

Events

updatefound: Fired any time theServiceWorkerRegistration.installing property acquires a new service worker.

Examples

In this example, the code first checks whether the browser supports service workers and if so registers one. Next, it adds anupdatefound listener 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, then theupdatefound event will not be fired.

if ("serviceWorker" in navigator) {  navigator.serviceWorker    .register("/sw.js")    .then((registration) => {      registration.addEventListener("updatefound", () => {        // If updatefound is fired, it means that there's        // a new service worker being installed.        const installingWorker = registration.installing;        console.log(          "A new service worker is being installed:",          installingWorker,        );        // You can listen for changes to the installing service worker's        // state via installingWorker.onstatechange      });    })    .catch((error) => {      console.error(`Service worker registration failed: ${error}`);    });} else {  console.error("Service workers are not supported.");}