FetchEvent.clientId

The clientId read-only property of the FetchEvent interface returns the id of the Client that the current service worker is controlling.

The Clients.get() method could then be passed this ID to retrieve the associated client.

Syntax

var myClientId = fetchEvent.clientId;

Value

A DOMString that represents the client ID.

Example

self.addEventListener('fetch', function(event) {
  console.log(event.clientId);
​});

Specifications

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

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
clientId
Experimental
Chrome Full support 49Edge Full support ≤79Firefox Full support 45
Notes
Full support 45
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 36Safari No support NoWebView Android Full support 49Chrome Android Full support 49Firefox Android Full support 45Opera Android Full support 36Safari iOS No support NoSamsung 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.

See also