The CanvasRenderingContext2D
.shadowColor
property of the Canvas 2D API specifies the color of shadows.
Be aware that the shadow's rendered opacity will be affected by the opacity of the fillStyle
color when filling, and of the strokeStyle
color when stroking.
Note: Shadows are only drawn if the shadowColor
property is set to a non-transparent value. One of the shadowBlur
, shadowOffsetX
, or shadowOffsetY
properties must be non-zero, as well.
Syntax
ctx.shadowColor = color;
Examples
Adding a shadow to shapes
This example adds a shadow to two squares; the first one is filled, and the second one is stroked. The shadowColor
property sets the shadows' color, while shadowOffsetX
and shadowOffsetY
set their position relative to the shapes.
HTML
<canvas id="canvas"></canvas>
JavaScript
const canvas = document.getElementById('canvas'); const ctx = canvas.getContext('2d'); // Shadow ctx.shadowColor = 'red'; ctx.shadowOffsetX = 10; ctx.shadowOffsetY = 10; // Filled rectangle ctx.fillRect(20, 20, 100, 100); // Stroked rectangle ctx.lineWidth = 6; ctx.strokeRect(170, 20, 100, 100);
Result
Shadows on translucent shapes
A shadow's opacity is affected by the transparency level of its parent object (even when shadowColor
specifies a completely opaque value). This example strokes and fills a rectangle with translucent colors.
HTML
<canvas id="canvas"></canvas>
JavaScript
The resulting alpha value of the fill shadow is .8 * .2
, or .16
. The alpha of the stroke shadow is .8 * .6
, or .48
.
const canvas = document.getElementById('canvas'); const ctx = canvas.getContext('2d'); // Shadow ctx.shadowColor = 'rgba(255, 0, 0, .8)'; ctx.shadowBlur = 8; ctx.shadowOffsetX = 30; ctx.shadowOffsetY = 20; // Filled rectangle ctx.fillStyle = 'rgba(0, 255, 0, .2)'; ctx.fillRect(10, 10, 150, 100); // Stroked rectangle ctx.lineWidth = 10; ctx.strokeStyle = 'rgba(0, 0, 255, .6)'; ctx.strokeRect(10, 10, 150, 100);
Result
Specifications
Specification | Status | Comment |
---|---|---|
HTML Living Standard The definition of 'CanvasRenderingContext2D.shadowColor' in that specification. |
Living Standard |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
shadowColor | Chrome Full support Yes | Edge Full support 12 | Firefox Full support 1.5 | IE Full support Yes | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 4 | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support Yes |
Legend
- Full support
- Full support
WebKit/Blink-specific notes
In WebKit- and Blink-based browsers, the non-standard and deprecated method ctx.setShadow()
is implemented besides this property.
setShadow(width, height, blur, color, alpha); setShadow(width, height, blur, graylevel, alpha); setShadow(width, height, blur, r, g, b, a); setShadow(width, height, blur, c, m, y, k, a);
See also
- The interface defining this property:
CanvasRenderingContext2D