The WebGLRenderingContext.canvas property is a read-only reference to the HTMLCanvasElement or OffscreenCanvas object that is associated with the context. It might be null if it is not associated with a <canvas> element or an OffscreenCanvas object.

Either a HTMLCanvasElement or OffscreenCanvas object or null.

Given this <canvas> element:

<canvas id="canvas"></canvas>

You can get back a reference to it from the WebGLRenderingContext using the canvas property:

const canvas = document.getElementById("canvas");
const gl = canvas.getContext("webgl");
gl.canvas; // HTMLCanvasElement

Example using the experimental OffscreenCanvas object.

const offscreen = new OffscreenCanvas(256, 256);
const gl = offscreen.getContext("webgl");
gl.canvas; // OffscreenCanvas

• CanvasRenderingContext2D.canvas
• The OffscreenCanvas interface