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The mask-position CSS property sets the initial position, relative to the mask position layer defined 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;

/*  values */
mask-position: 25% 75%;

/*  values */
mask-position: 0px 0px;
mask-position: 1cm 2cm;
mask-position: 10ch 8em;

/* Multiple values */
mask-position: 0px 0px, center;

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

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 typerepeatable list of simple list of length, percentage, or calc
Canonical orderthe unique non-ambiguous order defined by the formal grammar


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


Is a <position>, that is 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 syntax


<position> = [[ left | center | right | top | bottom | <length-percentage> ] | [ left | center | right | <length-percentage> ] [ top | center | bottom | <length-percentage> ] | [ center | [ left | right ] <length-percentage>? ] && [ center | [ top | bottom ] <length-percentage>? ]]

<length-percentage> = <length> | <percentage>



#wrapper {
  border: 1px solid black;
  width: 250px;
  height: 250px;

#masked {
  width: 250px;
  height: 250px;
  background: blue linear-gradient(red, blue);
  mask-image: url(;
  mask-repeat: no-repeat;
  mask-position: top right; /* Can be changed in the live sample */
  margin-bottom: 10px;


Specification Status Comment
CSS Masking Module Level 1
The definition of 'mask-position' in that specification.
Candidate Recommendation Initial definition

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 1.0-webkit 53.0 (53.0) ? ? 4.0-webkit
Feature Android Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile
Basic support ? 53.0 (53.0) ? ? ?

Document Tags and Contributors

 Contributors to this page: wbamberg, Sebastianz, chrisdavidmills, teoli
 Last updated by: wbamberg,