This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The mask-mode CSS property sets whether the mask reference defined by mask-image is treated as a luminance or alpha mask.

/* Keyword values */
mask-mode: alpha;
mask-mode: luminance;
mask-mode: match-source;

/* Multiple values */
mask-mode: alpha, match-source;

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

Initial valuematch-source
Applies toall elements; In SVG, it applies to container elements excluding the defs element and all graphics elements
Inheritedno
Mediavisual
Computed valueas specified
Animation typediscrete
Canonical orderper grammar

Syntax

The mask-mode property is specified as one or more of the keyword values listed below, separated by commas.

Values

alpha
This keyword indicates that the transparency (alpha channel) values of the mask layer image should be used as the mask values.
luminance
This keyword indicates that the luminance values of the mask layer image should be used as the mask values.
match-source

If the mask-image property is of type <mask-source>, the luminance values of the mask layer image should be used as the mask values.

If it is of type <image>, the alpha values of the mask layer image should be used as the mask values.

Formal syntax

<masking-mode>#

where
<masking-mode> = alpha | luminance | match-source

Example

CSS

#masked {
  width: 227px;
  height: 200px;
  background: blue linear-gradient(red, blue);
  mask-image: url(https://mdn.mozillademos.org/files/12668/MDN.svg);
  mask-mode: alpha; /* Can be changed in the live sample */
}

Result

Specifications

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

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Basic support
Experimental
Chrome No support NoEdge ? Firefox Full support 53IE No support NoOpera No support NoSafari No support NoWebView Android No support NoChrome Android ? Edge Mobile ? Firefox Android Full support 53Opera Android No support NoSafari iOS No support NoSamsung Internet Android No support No

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.

Document Tags and Contributors

Last updated by: ddbeck,