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
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Contributors to this page:
jpmedley,
jeffposnick,
chrisdavidmills,
ithinkihaveacat,
Sebastianz,
fscholz,
kscarfone
Last updated by:
jpmedley,