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 Standard
The definition of 'CanvasRenderingContext2D.globalCompositeOperation' in that specification.
Living Standard
Compositing and Blending Level 1 Candidate Recommendation

Browser compatibility

DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
globalCompositeOperationChrome Full support 1Edge Full support 12Firefox Full support 1.5IE Full support 9Opera Full support 9Safari Full support 2WebView Android Full support 1Chrome Android Full support 18Firefox Android Full support 4Opera Android Full support 10.1Safari iOS Full support 1Samsung Internet Android Full support 1.0

Legend

Full support
Full support
  • 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".

See also