ServiceWorker.state

The state read-only property of the ServiceWorker interface returns a string representing the current state of the service worker. It can be one of the following values: installing, installed, activating, activated, or redundant.

Syntax

someURL = ServiceWorker.state

Value

A ServiceWorkerState definition (see the spec.)

Examples

This code snippet is from the service worker registration-events sample (live demo). The code listens for any change in the ServiceWorker.state and returns its value.

var serviceWorker;
if (registration.installing) {
  serviceWorker = registration.installing;
  document.querySelector('#kind').textContent = 'installing';
} else if (registration.waiting) {
  serviceWorker = registration.waiting;
  document.querySelector('#kind').textContent = 'waiting';
} else if (registration.active) {
  serviceWorker = registration.active;
  document.querySelector('#kind').textContent = 'active';
}

if (serviceWorker) {
  logState(serviceWorker.state);
  serviceWorker.addEventListener('statechange', function(e) {
  logState(e.target.state);
  });
}

Specifications

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

Browser compatibility

DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
state
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 Extended Support Releases (ESR) before Firefox 78 ESR do not support service workers and the Push API.
IE No support NoOpera Full support 27Safari Full support 11.1WebView Android Full support 40Chrome Android Full support 40Firefox Android Full support 44Opera Android Full support 27Safari iOS Full support 11.3Samsung Internet Android Full support 4.0

Legend

Full support
Full support
No support
No support
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.