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This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

The id read-only property of the Client interface returns the universally unique identifier of the Client object.


var clientId =;




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

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 45.0[1] 44.0 (44.0)[2] 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) ? No support ? No support 45.0 [1]

Document Tags and Contributors

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