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

 

The ServiceWorker interface of the ServiceWorker API provides a reference to a service worker. Multiple browsing contexts (e.g. pages, workers, etc.) can be associated with the same service worker, each through a unique ServiceWorker object.

A ServiceWorker object is available in the ServiceWorkerRegistration.active property, and the ServiceWorkerContainer.controller property — this is a service worker that activated and controlling the page (the service worker has been successfully registered, and the controlled page has been reloaded.)

The ServiceWorker interface is dispatched a set of lifecycle events — install and activate — and functional events including fetch. A ServiceWorker object has an associated ServiceWorker.state, related to its lifecycle.

Properties

The ServiceWorker interface inherits properties from its parent, Worker.

ServiceWorker.scriptURL Read only
Returns the ServiceWorker serialized script URL defined as part of ServiceWorkerRegistration. The URL must be on the same origin as the document that registers the ServiceWorker.
ServiceWorker.state Read only
Returns the state of the service worker. It returns one of the following values: installing, installed, activating, activated, or redundant.

Event handlers

ServiceWorker.onstatechange Read only
An EventListener property called whenever an event of type statechange is fired; it is basically fired anytime the ServiceWorker.state changes.

Methods

The ServiceWorker interface inherits methods from its parent, Worker, with the exception of Worker.terminate — this should not be accessible from service workers.

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.

if ('serviceWorker' in navigator) {
    navigator.serviceWorker.register('service-worker.js', {
        scope: './'
    }).then(function (registration) {
        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);
            });
        }
    }).catch (function (error) {
        // Something went wrong during registration. The service-worker.js file
        // might be unavailable or contain a syntax error.
    });
} else {
    // The current browser doesn't support service workers.
}

Specifications

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

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung 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
scriptURL
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
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 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
onstatechange
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

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: duduindo,