This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

The SyncEvent interface represents a sync action that is dispatched on the ServiceWorkerGlobalScope of a ServiceWorker. 

This interface inherits from the ExtendableEvent interface.


Creates a new SyncEvent object.


Inherits properties from its ancestor, Event.

SyncEvent.tag Read only
Returns the developer-defined identifier for this SyncEvent.
SyncEvent.lastChance Read only
Returns true if the user agent will not make further synchronization attempts after the current attempt.


Inherits methods from its parent, ExtendableEvent


Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 49.0 ? ? ? ?
Feature Android Android Webview Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile Chrome for Android
Basic support Not supported Not supported ? ? ? ? ? 49.0


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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.

API Background Sync Interface Offline Reference Référence ServiceWorker SyncEvent Workers