WebGLRenderingContext: getContextAttributes() method

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

Note: This feature is available in Web Workers.

The WebGLRenderingContext.getContextAttributes() method returns a WebGLContextAttributes object that contains the actual context parameters. Might return null, if the context is lost.

Syntax

getContextAttributes()

Parameters

None.

Return value

A WebGLContextAttributes object that contains the actual context parameters, or null if the context is lost.

Examples

Given this <canvas> element

html

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

and given this WebGL context

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

the getContextAttributes method returns an object that describes the attributes set on this context, for example:

json

{
  "alpha": true,
  "antialias": true,
  "depth": true,
  "failIfMajorPerformanceCaveat": false,
  "powerPreference": "default",
  "premultipliedAlpha": true,
  "preserveDrawingBuffer": false,
  "stencil": false,
  "desynchronized": false
}

The context attributes can be set when creating the context using the HTMLCanvasElement.getContext() method:

canvas.getContext("webgl", { antialias: false, depth: false });

See getContext() for more information about the individual attributes.

Specifications

Specification
WebGL Specification # 5.14.2