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 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
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
|---|---|---|---|---|---|
| Basic support | 40.0 | 44.0 (44.0)[1] | No support | 24 | No support |
| Feature | Android | Android Webview | Firefox Mobile (Gecko) | Firefox OS | IE Mobile | Opera Mobile | Safari Mobile | Chrome for Android |
|---|---|---|---|---|---|---|---|---|
| Basic support | No support | No support | 44.0 (44.0) | (Yes) | No support | ? | No support | 40.0 |
[1] Service workers (and Push) have been disabled in the Firefox 45 and 52 Extended Support Releases (ESR.)