blur()
The blur()
CSS function applies a Gaussian blur to the input image. Its result is a <filter-function>
.
Try it
Syntax
The blur()
function applies a Gaussian blur to the elements on which it is applied.
blur(radius)
Parameters
radius
-
The radius of the blur, specified as a
<length>
. It defines the value of the standard deviation to the Gaussian function, i.e., how many pixels on the screen blend into each other; thus, a larger value will create more blur. A value of0
leaves the input unchanged. The initial value for interpolation is0
. Percentage values are invalid.
Setting a blur with pixels and with rem
blur(0) /* No effect */
blur(8px) /* Blur with 8px radius */
blur(1.17rem) /* Blur with 1.17rem radius */
SVG filter
The SVG <feGaussianBlur>
filter element can also be used to blur content. The filter's stdDeviation
attribute accepts up to two values enabling creating more complex blur values. To create an equivalent blur, we include one value for stdDeviation
. This SVG effect can then be referenced by ID:
<svg role="none">
<filter id="blur11">
<feGaussianBlur stdDeviation="1.1" edgeMode="duplicate" />
</filter>
</svg>
The following declarations produce the same effect:
filter: blur(1.1px);
filter: url(#blur11); /* with embedded SVG */
filter: url(folder/fileName.svg#blur11); /* external svg filter definition */
Examples
This example shows three images: the image with a blur()
filter function applied, the image with the equivalent SVG blur function applied, and the original images for comparison:
.filter {
filter: blur(3.5px);
}
<svg role="img" aria-label="Flag">
<filter id="blur">
<feGaussianBlur stdDeviation="3.5" edgeMode="duplicate" />
</filter>
<image
href="https://mdn.github.io/shared-assets/images/examples/progress-pride-flag.jpg"
xlink:href="https://mdn.github.io/shared-assets/images/examples/progress-pride-flag.jpg"
filter="url(#blur)" />
</svg>
Specifications
Specification |
---|
Filter Effects Module Level 1 # funcdef-filter-blur |
Browser compatibility
BCD tables only load in the browser
See also
- CSS filter effects module
- The other
<filter-function>
functions available to be used in values of thefilter
andbackdrop-filter
properties include: