index.md

---
title: -webkit-mask-position-y
slug: Web/CSS/-webkit-mask-position-y
page-type: css-property
status:
  - non-standard
browser-compat: css.properties.-webkit-mask-position-y
---

{{CSSRef}}{{Non-standard_header}}

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

## Syntax

```css
/* 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 */
-webkit-mask-position-y:
  50px,
  25%,
  -3em;

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

### 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 definition

{{CSSInfo}}

## Formal syntax

{{CSSSyntaxRaw(`-webkit-mask-position-y = [ <length-percentage> | top | center | bottom ]#`)}}

## Examples

### Vertically positioning a mask image

```css
.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 standard.

## Browser compatibility

{{Compat}}

## See also

{{cssxref("mask-position", "-webkit-mask-position")}}, {{cssxref("-webkit-mask-position-x")}}, {{cssxref("mask-origin", "-webkit-mask-origin")}}