Web/API/Client

The Client interface represents an executable context such as a Worker, or a SharedWorker. Window clients are represented by the more-specific WindowClient. You can get Client/WindowClient objects from methods such as Clients.matchAll() and Clients.get().

Methods

Client.postMessage(): Sends a message to the client.

Properties

Client.id Read only: The universally unique identifier of the client as a string.
Client.type Read only: The client's type as a string. It can be "window", "worker", or "sharedworker".
Client.url Read only: The URL of the client as a string.

Specifications

Specification	Status	Comment
Service WorkersThe definition of 'Client' in that specification.	Working Draft	Initial definition.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`Client` Experimental'	Chrome Full support 40	Edge Full support 17	Firefox 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 No	Opera Full support 27	Safari No support No	WebView Android Full support 40	Chrome Android Full support 40	Firefox Android Full support 44	Opera Android Full support 27	Safari iOS No support No	Samsung Internet Android Full support 4.0
`frameType` Experimental'	Chrome Full support 43	Edge Full support 17	Firefox 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 No	Opera Full support 30	Safari No support No	WebView Android Full support 43	Chrome Android Full support 43	Firefox Android Full support 44	Opera Android Full support 30	Safari iOS No support No	Samsung Internet Android Full support 4.0
`id` Experimental'	Chrome Full support 40	Edge Full support ≤79	Firefox 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 No	Opera Full support 27	Safari No support No	WebView Android Full support 40	Chrome Android Full support 40	Firefox Android Full support 44	Opera Android Full support 27	Safari iOS No support No	Samsung Internet Android Full support 4.0
`postMessage` Experimental'	Chrome Full support 45	Edge Full support ≤79	Firefox 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 No	Opera Full support 32	Safari No support No	WebView Android Full support 45	Chrome Android Full support 45	Firefox Android Full support 44	Opera Android Full support 32	Safari iOS No support No	Samsung Internet Android Full support 5.0
`type` Experimental'	Chrome Full support 60	Edge Full support ≤79	Firefox Full support 54	IE No support No	Opera Full support 47	Safari No support No	WebView Android Full support 60	Chrome Android Full support 60	Firefox Android Full support 54	Opera Android Full support 44	Safari iOS No support No	Samsung Internet Android Full support 8.0
`url` Experimental'	Chrome Full support 40	Edge Full support ≤79	Firefox 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 No	Opera Full support 27	Safari No support No	WebView Android Full support 40	Chrome Android Full support 40	Firefox Android Full support 44	Opera Android Full support 27	Safari iOS No support No	Samsung Internet Android Full support 4.0

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.