Worklet

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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.

Worklets allow static import of ECMAScript modules, if supported, using import. Dynamic import is disallowed by the specification — calling import() will throw.

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
`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
`SharedStorageWorklet`	For running private operations on cross-site data, without risk of data leakage.	Main thread	Shared Storage API

Note: Paint worklets, defined by the CSS Painting API, don't subclass Worklet. They are accessed through a regular Worklet object obtained using CSS.paintWorklet.

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.