border-image-slice property - CSS Reference

Definition and Usage

The border-image-slice CSS property divides the image specified by border-image-source in nine regions: the four corners, the four edges and the middle. It does this by specifying 4 inwards offsets.

Four values control the position of the slice lines. If some are not specified, they are inferred from the other with the usual 4-value syntax of CSS.

The middle is not used by the border itself but is used as a background-image if the keyword fill is set. The keyword can be set at any position in the property (before, after or between the other values).

The border-image-repeat, border-image-width, border-image-outset properties define how these images will be used.

The shorthand CSS property border-image may reset this property to its default value.

Initial 100%
Applies to all elements, except internal table elements when border-collapse is collapse
Inherited no
Percentages refer to the size of the border image
Media visual
Computed Value one to four percentage(s) (as specified) or absolute length(s), plus the keyword fill if specified
Animatable no
Canonical order the percentages or lengths, eventually followed by the keyword fill

Syntax

Formal syntax: [<number> | <percentage>]{1,4} && fill?

border-image-slice: slice                  /* One-value syntax   */  E.g. border-image-slice: 30%;
border-image-slice: horizontal vertical    /* Two-value syntax   */  E.g. border-image-slice: 10% 30%;
border-image-slice: top vertical bottom    /* Three-value syntax */  E.g. border-image-slice: 30 30% 45;
border-image-slice: top right bottom left  /* Four-value syntax  */  E.g. border-image-slice: 7 12 14 5;
border-image-slice: … fill /* The fill value can be placed between any value */ E.g. border-image-slice: 10% fill 7 12;
border-image-slice: inherit

Values

slice: Is a <number> or a <percentage> of the offset for the four slicing lines. Note that a <length> value is not allowed, and therefore invalid. The <number> represents pixels for raster images and coordinates for vector images. Also, <percentage> values are relative to the height or width of the image, whichever is adequate. Negative values are invalid and values greater than the relevant size, height or width, are clamped to 100%.
horizontal: Is a <number> or a <percentage> of the offset for the two horizontal slicing lines, the top and the bottom ones. Note that a <length> value is not allowed, and therefore invalid. The <number> represents pixels for raster images and coordinates for vector images. Also, <percentage> values are relative to the height or width of the image, whichever is adequate. Negative values are invalid and values greater than the relevant size, height or width, are clamped to 100%.
vertical: Is a <number> or a <percentage> of the offset for the two vertical slicing lines, the right and the left ones. Note that a <length> value is not allowed, and therefore invalid. The <number> represents pixels for raster images and coordinates for vector images. Also, <percentage> values are relative to the height or width of the image, whichever is adequate. Negative values are invalid and values greater than the relevant size, height or width, are clamped to 100%.
top: Is a <number> or a <percentage> of the offset for the top slicing line. Note that a <length> value is not allowed, and therefore invalid. The <number> represents pixels for raster images and coordinates for vector images. Also, <percentage> values are relative to the height or width of the image, whichever is adequate. Negative values are invalid and values greater than the relevant size, height or width, are clamped to 100%.
bottom: Is a <number> or a <percentage> of the offset for the bottom slicing line. Note that a <length> value is not allowed, and therefore invalid. The <number> represents pixels for raster images and coordinates for vector images. Also, <percentage> values are relative to the height or width of the image, whichever is adequate. Negative values are invalid and values greater than the relevant size, height or width, are clamped to 100%.
right: Is a <number> or a <percentage> of the offset for the right slicing line. Note that a <length> value is not allowed, and therefore invalid. The <number> represents pixels for raster images and coordinates for vector images. Also, <percentage> values are relative to the height or width of the image, whichever is adequate. Negative values are invalid and values greater than the relevant size, height or width, are clamped to 100%.
left: Is a <number> or a <percentage> of the offset for the left slicing line. Note that a <length> value is not allowed, and therefore invalid. The <number> represents pixels for raster images and coordinates for vector images. Also, <percentage> values are relative to the height or width of the image, whichever is adequate. Negative values are invalid and values greater than the relevant size, height or width, are clamped to 100%.
fill: Is a keyword whose presence forces the use of the middle image slice to be displayed over the background image, its size and height are resized like those of the top and left image slices, respectively.
inherit: Is a keyword indicating that all four values are inherited from their parent's element calculated value.