Baseline 2023

Newly available

Since December 2023, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

The mask-position CSS property sets the initial position, relative to the mask position layer set by mask-origin, for each defined mask image.


/* Keyword values */
mask-position: top;
mask-position: bottom;
mask-position: left;
mask-position: right;
mask-position: center;

/* <position> values */
mask-position: 25% 75%;
mask-position: 0px 0px;
mask-position: 10% 8em;

/* Multiple values */
mask-position: top right;
  1rem 1rem,

/* Global values */
mask-position: inherit;
mask-position: initial;
mask-position: revert;
mask-position: revert-layer;
mask-position: unset;

One or more <position> values, separated by commas.



One to four values representing a 2D position regarding the edges of the element's box. Relative or absolute offsets can be given. Note that the position can be set outside of the element's box.

Formal definition

Initial value0% 0%
Applies toall elements; In SVG, it applies to container elements excluding the <defs> element and all graphics elements
Percentagesrefer to size of mask painting area minus size of mask layer image (see the text for background-position)
Computed valueConsists of two keywords representing the origin and two offsets from that origin, each given as an absolute length (if given a <length>), otherwise as a percentage.
Animation typea repeatable list

Formal syntax

mask-position = 

<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> ]

<length-percentage> =
<length> |


Setting mask position

Change the mask-position value to any of the allowed values detailed above. If viewing the example in a Chromium-based browser change the value of -webkit-mask-position.


CSS Masking Module Level 1
# the-mask-position

Browser compatibility

BCD tables only load in the browser

See also