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

The installing property of the ServiceWorkerRegistration interface returns a service worker whose ServiceWorker.state is installing. This property is initially set to null.

Note: This feature is available in Web Workers.


sw = ServiceWorker.installing 


A ServiceWorker object, if it is currently in an installing state.


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

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 40.0 (Yes)[2] 44.0 (44.0)[1] No support ? No support
Available in web workers (Yes) ? 44.0 (44.0)[1] No support ? 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
Available in web workers ? ? (Yes) ? No support ? No support ?

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

[2] Service workers is available in Microsoft Edge starting EdgeHTML 16 behind a flag.

See also

Document Tags and Contributors

 Contributors to this page: abbycar, chrisdavidmills, jpmedley, fscholz, kscarfone
 Last updated by: abbycar,