-webkit-mask-position-y

Non-standard
This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

The -webkit-mask-position-y CSS property sets the initial vertical position of a mask image.

/* Keyword values */
-webkit-mask-position-y: top;
-webkit-mask-position-y: center;
-webkit-mask-position-y: bottom;
/* <percentage> values */
-webkit-mask-position-y: 100%;
-webkit-mask-position-y: -50%;
/* <length> values */
-webkit-mask-position-y: 50px;
-webkit-mask-position-y: -1cm;
/* Multiple values values */
-webkit-mask-position-y: 50px, 25%, -3em;
/* Global values */
-webkit-mask-position-y: inherit;
-webkit-mask-position-y: initial;
-webkit-mask-position-y: unset;

Initial value	`0%`
Applies to	all elements
Inherited	no
Percentages	refer to the size of the box itself
Media	visual
Computed value	for `<length>` the absolute value, otherwise a percentage
Animation type	discrete
Canonical order	order of appearance in the formal grammar of the values

Syntax

Values

<length-percentage>: A length indicating the position of the top side of the image relative to the box's top padding edge. Percentages are calculated against the vertical dimension of the box padding area. A value of 0% means the top edge of the image is aligned with the box's top padding edge and a value of 100% means the bottom edge of the image is aligned with the box's bottom padding edge.
top: Equivalent to 0%.
bottom: Equivalent to 100%.
center: Equivalent to 50%.

Formal syntax

[ <length-percentage> | top | center | bottom ]#where 
<length-percentage> = <length> | <percentage>

Examples

.exampleOne {
  -webkit-mask-image: url(mask.png);
  -webkit-mask-position-y: bottom;
}
.exampleTwo {
  -webkit-mask-image: url(mask.png);
  -webkit-mask-position-y: 25%;
}

Specifications

Not part of any specification.

Feature	Chrome	Firefox (Gecko)	Internet Explorer	Opera	Safari (WebKit)
Basic support	1.0	No support	No support	No support	4.0

Feature	Android	Firefox Mobile (Gecko)	IE Phone	Opera Mobile	Safari Mobile
Basic support	?	No support	No support	No support	?