The CanvasRenderingContext2D.shadowOffsetY property of the Canvas 2D API specifies the distance that shadows will be offset vertically.

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.


ctx.shadowOffsetY = offset;
A float specifying the distance that shadows will be offset vertically. Positive values are down, and negative are up. The default value is 0 (no vertical offset). Infinity and NaN values are ignored.


Moving a shadow vertically

This example adds a blurred shadow to a rectangle. The shadowColor property sets its color, shadowOffsetY sets its offset 25 units towards the bottom, and shadowBlur gives it a blur level of 10.


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


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

// Shadow
ctx.shadowColor = 'red';
ctx.shadowOffsetY = 25;
ctx.shadowBlur = 10;

// Rectangle
ctx.fillStyle = 'blue';
ctx.fillRect(20, 20, 150, 80);



Specification Status Comment
HTML Living Standard
The definition of 'CanvasRenderingContext2D.shadowOffsetY' in that specification.
Living Standard  

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
shadowOffsetYChrome Full support YesEdge Full support 12Firefox Full support 1.5IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yes


Full support  
Full support

See also