---
title: shadowBlur
framework: webkitjs
role: symbol
role_heading: Instance Property
path: webkitjs/canvasrenderingcontext2d/1632236-shadowblur
---

# shadowBlur

A floating-point number that controls the degree of Gaussian blur applied to shadows.

## Declaration

```data
attribute unrestricted float shadowBlur;
```

## Discussion

Discussion If shadows are enabled, each shadow has a Gaussian blur applied to its alpha value, with a standard deviation of shadowBlur. The shadowBlur value must be a positive number, and may be zero. Shadows are cast if the value of the shadowBlur property is nonzero and the alpha value of shadowColor is nonzero.

## See Also

### Working with Shadows

- [clearShadow](webkitjs/canvasrenderingcontext2d/1634057-clearshadow.md)
- [shadowColor](webkitjs/canvasrenderingcontext2d/1629275-shadowcolor.md)
- [shadowOffsetX](webkitjs/canvasrenderingcontext2d/1632399-shadowoffsetx.md)
- [shadowOffsetY](webkitjs/canvasrenderingcontext2d/1633455-shadowoffsety.md)