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ServiceWorkerContainer.controller

This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

The controller read-only property of the ServiceWorkerContainer interface returns a ServiceWorker object if its state is activated (the same object returned by ServiceWorkerRegistration.active). This property returns null if the request is a force refresh (Shift + refresh) or if there is no active worker.

Syntax

var myController = navigator.serviceWorker.controller;

Value

A ServiceWorker object.

Example

if ('serviceWorker' in navigator) {
  // Do a one-off check to see if a service worker's in control.
  if (navigator.serviceWorker.controller) {
    console.log('This page is currently controlled by:',
      navigator.serviceWorker.controller);
  } else {
    console.log('This page is not currently controlled ' +
      'by a service worker.');
  }
} else {
  console.log('Service workers are not supported.');
}

Specifications

Specification Status Comment
Service Workers
The definition of 'ServiceWorkerRegistration.controller' in that specification.
Editor's Draft Initial definition

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 40 44.0 (44.0)[1] No support 27 No support
Feature Android Webview Chrome for Android Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile
Basic support 40 40 44.0 (44.0) (Yes) No support 27 No support

[1] Service workers (and Push) have been disabled in the Firefox 45 and 52 Extended Support Releases (ESR.)

Document Tags and Contributors

 Last updated by: jpmedley,