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

The ServiceWorkerContainer interface of the ServiceWorker API provides an object representing the service worker as an overall unit in the network ecosystem, including facilities to register, unregister and update service workers, and access the state of service workers and their registrations.

Most importantly, it exposes the ServiceWorkerContainer.register() method used to register service workers, and the ServiceWorkerContainer.controller property used to determine whether or not the current page is actively controlled.

Properties

ServiceWorkerContainer.controller Read only
Returns a ServiceWorker object if its state is activated (the same object returned by ServiceWorkerRegistration.active). This property returns null during a force-refresh request (Shift + refresh) or if there is no active worker.
ServiceWorkerContainer.ready Read only
Provides a way of delaying code execution until a service worker is active. It returns a Promise that will never reject, and which waits indefinitely until the ServiceWorkerRegistration associated with the current page has an ServiceWorkerRegistration.active worker. Once that condition is met, it resolves with the ServiceWorkerRegistration.

Event handlers

ServiceWorkerContainer.oncontrollerchange
Fired whenever a controllerchange event occurs — when the document's associated ServiceWorkerRegistration acquires a new active worker.
ServiceWorkerContainer.onerror
Fired whenever an error event occurs in the associated service workers.
ServiceWorkerContainer.onmessage
Fired whenever a message event occurs — when incoming messages are received to the ServiceWorkerContainer object (e.g. via a MessagePort.postMessage() call.)

Methods

ServiceWorkerContainer.register() 
Creates or updates a ServiceWorkerRegistration for the given scriptURL.
ServiceWorkerContainer.getRegistration()
Gets a ServiceWorkerRegistration object whose scope matches the provided document URL.  If the method can't return a ServiceWorkerRegistration, it returns a Promise
ServiceWorkerContainer.getRegistrations()
Returns all ServiceWorkerRegistration objects associated with a ServiceWorkerContainer in an array.  If the method can't return ServiceWorkerRegistration objects, it returns a Promise

Examples

The example below first checks to see if the browser supports service workers. If supported, the code registers the service worker and determines if the page is actively controlled by the service worker. If it isn't, it prompts the user to reload the page so the service worker can take control. The code also reports any registration failures.

if ('serviceWorker' in navigator) {
  // Register a service worker hosted at the root of the
  // site using the default scope.
  navigator.serviceWorker.register('/sw.js').then(function(registration) {
    console.log('Service worker registration succeeded:', registration);

    // At this point, you can optionally do something 
    // with registration. See https://developer.mozilla.org/en-US/docs/Web/API/ServiceWorkerRegistration
  }).catch(function(error) {
    console.log('Service worker registration failed:', error);
  });

  // Independent of the registration, let's also display
  // information about whether the current page is controlled
  // by an existing service worker, and when that
  // controller changes.

  // First, do a one-off check if there's currently a
  // service worker in control.
  if (navigator.serviceWorker.controller) {
    console.log('This page is currently controlled by:', navigator.serviceWorker.controller);
  }

  // Then, register a handler to detect when a new or
  // updated service worker takes control.
  navigator.serviceWorker.oncontrollerchange = function() {
    console.log('This page is now controlled by:', navigator.serviceWorker.controller);
  };
} else {
  console.log('Service workers are not supported.');
}

Specifications

Specification Status Comment
Service Workers
The definition of 'ServiceWorkerContainer' in that specification.
Working Draft Initial definition.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung Internet
Basic support
Experimental
Chrome Full support 40Edge Full support 17
Full support 17
Full support 16
Disabled
Disabled From version 16: this feature is behind the Enable service workers preference.
Firefox Full support 44
Notes
Full support 44
Notes
Notes Service workers (and Push) have been disabled in the Firefox 45 and 52 Extended Support Releases (ESR).
IE No support NoOpera Full support 27Safari Full support 11.1WebView Android Full support 40Chrome Android Full support 40Edge Mobile ? Firefox Android Full support 44Opera Android Full support 27Safari iOS Full support 11.1Samsung Internet Android Full support 4.0
controller
Experimental
Chrome Full support 40Edge Full support 17
Full support 17
Full support 16
Disabled
Disabled From version 16: this feature is behind the Enable service workers preference.
Firefox Full support 44
Notes
Full support 44
Notes
Notes Service workers (and Push) have been disabled in the Firefox 45 and 52 Extended Support Releases (ESR).
IE No support NoOpera Full support 27Safari Full support 11.1WebView Android Full support 40Chrome Android Full support 40Edge Mobile ? Firefox Android Full support 44Opera Android Full support 27Safari iOS Full support 11.1Samsung Internet Android Full support 4.0
ready
Experimental
Chrome Full support 40Edge Full support 17
Full support 17
Full support 16
Disabled
Disabled From version 16: this feature is behind the Enable service workers preference.
Firefox Full support 44
Notes
Full support 44
Notes
Notes Service workers (and Push) have been disabled in the Firefox 45 and 52 Extended Support Releases (ESR).
IE No support NoOpera Full support 27Safari Full support 11.1WebView Android Full support 40Chrome Android Full support 40Edge Mobile ? Firefox Android Full support 44Opera Android Full support 27Safari iOS Full support 11.1Samsung Internet Android Full support 4.0
oncontrollerchange
Experimental
Chrome Full support 40Edge Full support 17
Full support 17
Full support 16
Disabled
Disabled From version 16: this feature is behind the Enable service workers preference.
Firefox Full support 44
Notes
Full support 44
Notes
Notes Service workers (and Push) have been disabled in the Firefox 45 and 52 Extended Support Releases (ESR).
IE No support NoOpera Full support 27Safari Full support 11.1WebView Android Full support 40Chrome Android Full support 40Edge Mobile ? Firefox Android Full support 44Opera Android Full support 27Safari iOS Full support 11.1Samsung Internet Android Full support 4.0
onerror
Experimental
Chrome Full support 40Edge Full support 17
Full support 17
Full support 16
Disabled
Disabled From version 16: this feature is behind the Enable service workers preference.
Firefox Full support 44
Notes
Full support 44
Notes
Notes Service workers (and Push) have been disabled in the Firefox 45 and 52 Extended Support Releases (ESR).
IE No support NoOpera Full support 27Safari Full support 11.1WebView Android Full support 40Chrome Android Full support 40Edge Mobile ? Firefox Android Full support 44Opera Android Full support 27Safari iOS Full support 11.1Samsung Internet Android Full support 4.0
onmessage
Experimental
Chrome Full support 40Edge Full support 17
Full support 17
Full support 16
Disabled
Disabled From version 16: this feature is behind the Enable service workers preference.
Firefox Full support 44
Notes
Full support 44
Notes
Notes Service workers (and Push) have been disabled in the Firefox 45 and 52 Extended Support Releases (ESR).
IE No support NoOpera Full support 27Safari Full support 11.1WebView Android Full support 40Chrome Android Full support 40Edge Mobile ? Firefox Android Full support 44Opera Android Full support 27Safari iOS Full support 11.1Samsung Internet Android Full support 4.0
register
Experimental
Chrome Full support 40Edge Full support 17
Full support 17
Full support 16
Disabled
Disabled From version 16: this feature is behind the Enable service workers preference.
Firefox Full support 44
Notes
Full support 44
Notes
Notes Service workers (and Push) have been disabled in the Firefox 45 and 52 Extended Support Releases (ESR).
IE No support NoOpera Full support 27Safari Full support 11.1WebView Android Full support 40Chrome Android Full support 40Edge Mobile ? Firefox Android Full support 44Opera Android Full support 27Safari iOS Full support 11.1Samsung Internet Android Full support 4.0
getRegistration
Experimental
Chrome Full support 40Edge Full support 17
Full support 17
Full support 16
Disabled
Disabled From version 16: this feature is behind the Enable service workers preference.
Firefox Full support 44
Notes
Full support 44
Notes
Notes Service workers (and Push) have been disabled in the Firefox 45 and 52 Extended Support Releases (ESR).
IE No support NoOpera Full support 27Safari Full support 11.1WebView Android Full support 40Chrome Android Full support 40Edge Mobile ? Firefox Android Full support 44Opera Android Full support 27Safari iOS Full support 11.1Samsung Internet Android Full support 4.0
getRegistrations
Experimental
Chrome Full support 40Edge Full support 17
Full support 17
Full support 16
Disabled
Disabled From version 16: this feature is behind the Enable service workers preference.
Firefox Full support 44
Notes
Full support 44
Notes
Notes Service workers (and Push) have been disabled in the Firefox 45 and 52 Extended Support Releases (ESR).
IE No support NoOpera Full support 27Safari Full support 11.1WebView Android Full support 40Chrome Android Full support 40Edge Mobile ? Firefox Android Full support 44Opera Android Full support 27Safari iOS Full support 11.1Samsung Internet Android Full support 4.0
onmessageerrorChrome ? Edge ? Firefox ? IE ? Opera ? Safari ? WebView Android ? Chrome Android ? Edge Mobile ? Firefox Android ? Opera Android ? Safari iOS ? Samsung Internet Android ?
startMessagesChrome ? Edge ? Firefox ? IE ? Opera ? Safari ? WebView Android ? Chrome Android ? Edge Mobile ? Firefox Android ? Opera Android ? Safari iOS ? Samsung Internet Android ?

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.
See implementation notes.
See implementation notes.
User must explicitly enable this feature.
User must explicitly enable this feature.

See also

Document Tags and Contributors

Last updated by: fscholz,