<mask>

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since January 2020.

The <mask> element defines an alpha mask for compositing the current object into the background. A mask is used/referenced using the mask property.

Example

html,
body,
svg {
  height: 100%;
}

html

<svg viewBox="-10 -10 120 120">
  <rect x="-10" y="-10" width="120" height="120" fill="blue" />
  <mask id="myMask">
    <!-- Everything under a white pixel will be visible -->
    <rect x="0" y="0" width="100" height="100" fill="white" />

    <!-- Everything under a black pixel will be invisible -->
    <path
      d="M10,35 A20,20,0,0,1,50,35 A20,20,0,0,1,90,35 Q90,65,50,95 Q10,65,10,35 Z"
      fill="black" />
  </mask>

  <polygon points="-10,110 110,110 110,-10" fill="orange" />

  <!-- with this mask applied, we "punch" a heart shape hole into the circle -->
  <circle cx="50" cy="50" r="50" fill="purple" mask="url(#myMask)" />
</svg>

Attributes

height: This attribute defines the height of the masking area. Value type: <length> ; Default value: 120%; Animatable: yes
maskContentUnits: This attribute defines the coordinate system for the contents of the <mask>. Value type: userSpaceOnUse|objectBoundingBox ; Default value: userSpaceOnUse; Animatable: yes
maskUnits: This attribute defines the coordinate system for attributes x, y, width and height on the <mask>. Value type: userSpaceOnUse|objectBoundingBox ; Default value: objectBoundingBox; Animatable: yes
x: This attribute defines the x-axis coordinate of the top-left corner of the masking area. Value type: <coordinate> ; Default value: -10%; Animatable: yes
y: This attribute defines the y-axis coordinate of the top-left corner of the masking area. Value type: <coordinate> ; Default value: -10%; Animatable: yes
width: This attribute defines the width of the masking area. Value type: <length> ; Default value: 120%; Animatable: yes

Usage context

Categories	Container element
Permitted content	Any number of the following elements, in any order: Animation elements Descriptive elements Shape elements Structural elements Gradient elements `<a>`, `<clipPath>`, `<cursor>`, `<filter>`, `<font>`, `<font-face>`, `<foreignObject>`, `<image>`, `<marker>`, `<mask>`, `<pattern>`, `<script>`, `<style>`, `<switch>`, `<text>`, `<view>`

Specifications

Specification
CSS Masking Module Level 1 # MaskElement

Browser compatibility

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