Worklet

Experimental

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

The Worklet interface is a lightweight version of Web Workers and gives developers access to low-level parts of the rendering pipeline. With Worklets, you can run JavaScript and WebAssembly code to do graphics rendering or audio processing where high performance is required.

Worklet types

Worklets are restricted to specific use cases; they cannot be used for arbitrary computations like Web Workers. The Worklet interface abstracts properties and methods common to all kind of worklets, and cannot be created directly. Instead, you can use one of the following classes:

Name Description Location Specification
PaintWorklet

For programmatically generating an image where a CSS property expects a file. Access this interface through CSS.paintWorklet.

Chrome: Main thread
Gecko: Paint thread
CSS Painting API
AudioWorklet For audio processing with custom AudioNodes. Web Audio render thread Web Audio API
AnimationWorklet For creating scroll-linked and other high performance procedural animations. Compositor thread CSS Animation Worklet API
LayoutWorklet For defining the positioning and dimensions of custom elements. CSS Layout API

For 3D rendering with WebGL, you don't use Worklets. Instead, you write Vertex Shaders and Fragment Shaders using GLSL code, and those shaders will then run on the graphics card.

Properties

The Worklet interface does not define any properties.

Methods

Worklet.addModule() This is an experimental API that should not be used in production code.
Adds the script module at the given URL to the current worklet.

Specifications

Specification
HTML Living Standard
The definition of 'Worklet' in that specification.

Browser compatibility

BCD tables only load in the browser

See also