Web/API/CanvasRenderingContext2D/globalCompositeOperation

The CanvasRenderingContext2D.globalCompositeOperation property of the Canvas 2D API sets the type of compositing operation to apply when drawing new shapes.

See also Compositing and clipping in the Canvas Tutorial.

Syntax

ctx.globalCompositeOperation = type;

type is a String identifying which of the compositing or blending mode operations to use.

Types

Examples

Changing the composite operation

This example uses the globalCompositeOperation property to draw two rectangles that exclude themselves where they overlap.

HTML

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

JavaScript

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');

ctx.globalCompositeOperation = 'xor';

ctx.fillStyle = 'blue';
ctx.fillRect(10, 10, 100, 100);

ctx.fillStyle = 'red';
ctx.fillRect(50, 50, 100, 100);

Result

Specifications

Specification	Status	Comment
HTML Living StandardThe definition of 'CanvasRenderingContext2D.globalCompositeOperation' in that specification.	Living Standard
Compositing and Blending Level 1	Candidate Recommendation

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`globalCompositeOperation`	Chrome Full support 1	Edge Full support 12	Firefox Full support 1.5	IE Full support 9	Opera Full support 9	Safari Full support 2	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0

Legend

Full support: Full support

WebKit/Blink-specific notes

In WebKit- and Blink-based Browsers, a non-standard and deprecated method ctx.setCompositeOperation() is implemented besides this property.
Support for "plus-darker" and "darker" were removed in Chrome 48. Developers looking for a replacement should use "darken".

Gecko-specific notes

An early Canvas specification draft specified the value "darker". However, Firefox removed support for "darker" in version 4 (bug 571532). See also this blog post that suggests using "difference" as a way to achieve a similar affect to "darker".