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

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

Note: This feature is available in Web Workers.


sw = ServiceWorker.waiting 


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


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

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support40



442 No27 No
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support4040 ?4427 No4.0

1. From version 16: this feature is behind the Enable service workers preference.

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

See also

Document Tags and Contributors

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