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.

Instance properties

The Worklet interface does not define any properties.

Instance methods


Adds the script module at the given URL to the current worklet.


HTML Standard
# worklets-worklet

Browser compatibility

BCD tables only load in the browser

See also