ServiceWorkerGlobalScope.onsync

The ServiceWorkerGlobalScope.onsync event of the ServiceWorkerGlobalScope interface is fired whenever a SyncEvent event occurs. This is triggered when a call to SyncManager.register is made from a service worker client page. The attempt to sync is made either immediately if the network is available or as soon as the network becomes available. 

Syntax

ServiceWorkerGlobalScope.onsync = function(SyncEvent) { ... }
self.addEventListener('sync', function(SyncEvent) { ... })

Specifications

Specification
Web Background Synchronization

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
onsync
Experimental
Chrome Full support 49Edge Full support ≤79Firefox 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 24Safari Full support 11.1WebView Android Full support 49Chrome Android Full support 49Firefox Android Full support 44Opera Android Full support 24Safari iOS Full support 11.3Samsung Internet Android Full support 5.0

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.