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.
For certain XUL elements and pseudo-elements that use an image from the list-style-image property, this property specifies a region of the image that is used in place of the whole image. This allows elements to use different pieces of the same image to improve performance.
/* Keyword value */ -moz-image-region: auto; /* <shape> value */ -moz-image-region: rect(0, 8px, 4px, 4px); /* Global values */ -moz-image-region: inherit; -moz-image-region: initial; -moz-image-region: unset;
The syntax is similar to the clip property. All four values are relative to the upper left corner of the image.
| Initial value | auto | 
|---|---|
| Applies to | XUL <image>elements and:-moz-tree-image,:-moz-tree-twisty, and:-moz-tree-checkboxpseudo-elements. Note:-moz-image-regiononly works with<image>elements where the icon is specified usinglist-style-image. It will not work with XUL<image src="url" />. | 
| Inherited | yes | 
| Media | visual | 
| Computed value | as specified | 
| Animation type | discrete | 
| Canonical order | the unique non-ambiguous order defined by the formal grammar | 
Note: For a system that works on any background, see -moz-image-rect().
Syntax
Values
- auto
- Automatically defines the region of the image to use.
- <shape>
- A shape defining the part of the image to use. The rect()function defines a rectangle to use as shape. Its parameters define the top, right, bottom, and left offsets of the edges of the image, in this order.
Formal syntax
<shape> | autowhere
<shape> = rect(<top>, <right>, <bottom>, <left>)
Examples
#example-button {
  /* display only the 4x4 area from the top left of this image */
  list-style-image: url("chrome://example/skin/example.png");
  -moz-image-region: rect(0px, 4px, 4px, 0px);
}
#example-button:hover {
  /* use the 4x4 area to the right of the first for the hovered button */
  -moz-image-region: rect(0px, 8px, 4px, 4px);
}
Specifications
Not part of any specification.
Browser compatibility
| Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari | 
|---|---|---|---|---|---|---|
| Basic support | No support | No support | (Yes)-moz | No support | No support | No support | 
| Feature | Android | Edge | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile | 
|---|---|---|---|---|---|---|
| Basic support | No support | No support | (Yes)-moz | No support | No support | No support |