Worklet.addModule()

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The addModule() method of the Worklet interface loads the module in the given JavaScript file and adds it to the current Worklet.

Syntax

addPromise = worklet.addModule(moduleURL);
addPromise = worklet.addModule(moduleURL, options);

Parameters

moduleURL
A String containing the URL of a JavaScript file with the module to add.
options Optional
An object with any of the following options:
  • credentials: A RequestCredentials value that indicates whether to send credentials (e.g. cookies and HTTP authentification) when loading the module. Can be one of "omit", "same-origin", or "include". Defaults to "same-origin". See also Request.credentials.

Return value

A Promise that resolves once the module from the given URL has been added. The promise doesn't return any value.

Exceptions

If addModule() fails, it rejects the promise, delivering one of the following errors to the rejection handler.

AbortError
The specified script is invalid or could not be loaded.
SyntaxError
The specified moduleURL is invalid.

Examples

AudioWorklet example

const audioCtx = new AudioContext();
const audioWorklet = audioCtx.audioWorklet;
await audioWorklet.addModule('modules/bypassFilter.js', {
  credentials: 'omit',
});

PaintWorklet example

CSS.paintWorklet.addModule('https://mdn.github.io/houdini-examples/cssPaint/intro/worklets/hilite.js');

Once a paintWorklet is included, the CSS paint() function can be used to include the image created by the worklet:

@supports (background-image: paint(id)) {
  h1 {
      background-image: paint(hollowHighlights, filled, 3px);
  }
}

Specifications

Specification Status Comment
Worklets Level 1
The definition of 'addModule()' in that specification.
Working Draft

Browser compatibility

DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
addModule
Experimental
Chrome Full support 65Edge Full support 79Firefox No support No
Notes Disabled
No support No
Notes Disabled
Notes Available only in Firefox Nightly.
Disabled This feature is behind the dom.worklet.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support 52Safari No support NoWebView Android Full support 65Chrome Android Full support 65Firefox Android No support No
Notes Disabled
No support No
Notes Disabled
Notes Available only in Firefox Nightly.
Disabled This feature is behind the dom.worklet.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 47Safari iOS No support NoSamsung Internet Android Full support 9.0

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.
User must explicitly enable this feature.
User must explicitly enable this feature.