mask
Baseline2023
Newly available
SinceDecember 2023,this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.
Themask
CSSshorthand propertyhides an element (partially or fully) by masking or clipping the image at specific points.
Note:As well as the properties listed below, themask
shorthand also resetsmask-border
to its initial value. It is therefore recommended to use themask
shorthand rather than other shorthands or the individual properties to override any mask settings earlier in the cascade. This will ensure thatmask-border
has also been reset to allow the new styles to take effect.
Constituent properties
This property is a shorthand for the following CSS properties:
Syntax
/* Keyword values */
mask: none;
/* Image values */
mask: url(mask.png); /* Pixel image used as mask */
mask: url(masks.svg#star); /* Element within SVG graphic used as mask */
/* Combined values */
mask: url(masks.svg#star) luminance; /* Element within SVG graphic used as luminance mask */
mask: url(masks.svg#star) 40px 20px; /* Element within SVG graphic used as mask positioned 40px from the top and 20px from the left */
mask: url(masks.svg#star) 0 0/50px 50px; /* Element within SVG graphic used as mask with a width and height of 50px */
mask: url(masks.svg#star) repeat-x; /* Element within SVG graphic used as horizontally repeated mask */
mask: url(masks.svg#star) stroke-box; /* Element within SVG graphic used as mask extending to the box enclosed by the stroke */
mask: url(masks.svg#star) exclude; /* Element within SVG graphic used as mask and combined with background using non-overlapping parts */
/* Global values */
mask: inherit;
mask: initial;
mask: revert;
mask: revert-layer;
mask: unset;
/* Multiple masks */
mask:
url(masks.svg#star) left / 16px repeat-y,
/* Element within SVG graphic is used as a mask on the left-hand side with a width of 16px */
url(masks.svg#circle) right / 16px repeat-y; /* Element within SVG graphic is used as a mask on the right-hand side with a width of 16px */
Values
<mask-reference>
-
Sets the mask image source. See
mask-image
. <masking-mode>
-
Sets the masking mode of the mask image. See
mask-mode
. <position>
-
Sets the position of the mask image. See
mask-position
. <bg-size>
-
Sets the size of the mask image. See
mask-size
. <repeat-style>
-
Sets the repetition of the mask image. See
mask-repeat
. <geometry-box>
-
If only one
<geometry-box>
value is given, it sets bothmask-origin
andmask-clip
.If two<geometry-box>
values are present, then the first setsmask-origin
and the second setsmask-clip
. <geometry-box> | no-clip
-
Sets the area that is affected by the mask image. See
mask-clip
. <compositing-operator>
-
Sets the compositing operation used on the current mask layer. See
mask-composite
.
Formal definition
Initial value | as each of the properties of the shorthand:
|
---|---|
Applies to | all elements; In SVG, it applies to container elements excluding the<defs> element and all graphics elements |
Inherited | no |
Percentages | as each of the properties of the shorthand:
|
Computed value | as each of the properties of the shorthand:
|
Animation type | as each of the properties of the shorthand:
|
Createsstacking context | yes |
Formal syntax
mask =
<mask-layer>#
<mask-layer> =
<mask-reference>||
<position>[/<bg-size>]?||
<repeat-style>||
<geometry-box>||
[<geometry-box>|no-clip]||
<compositing-operator>||
<masking-mode>
<mask-reference> =
none|
<image>|
<mask-source>
<position> =
[left|center|right|top|bottom|<length-percentage>]|
[left|center|right]&&[top|center|bottom]|
[left|center|right|<length-percentage>][top|center|bottom|<length-percentage>]|
[[left|right]<length-percentage>]&&[[top|bottom]<length-percentage>]
<bg-size> =
[<length-percentage [0,∞]>|auto]{1,2}|
cover|
contain
<repeat-style> =
repeat-x|
repeat-y|
[repeat|space|round|no-repeat]{1,2}
<geometry-box> =
<shape-box>|
fill-box|
stroke-box|
view-box
<compositing-operator> =
add|
subtract|
intersect|
exclude
<masking-mode> =
Alpha|
luminance|
match-source
<image> =
<url>|
<gradient>
<mask-source> =
<url>
<length-percentage> =
<length>|
<percentage>
<shape-box> =
<visual-box>|
margin-box
<url> =
<url()>|
<src()>
<visual-box> =
content-box|
padding-box|
border-box
<url()> =
url(<string><url-modifier>*)|
<url-token>
<src()> =
src(<string><url-modifier>*)
Examples
Masking an image
.target {
mask: url(#c1) luminance;
}
.another-target {
mask: url(resources.svg#c1) 50px 30px/10px 10px repeat-x exclude;
}
Specifications
Specification |
---|
CSS Masking Module Level 1 #the-mask |
Browser compatibility
BCD tables only load in the browser