border-image

The border-image CSS property draws an image around a given element. It replaces the element's regular border.

Note: You should specify a separate border-style in case the border image fails to load. Although the specification doesn't strictly require it, some browsers don't render the border image if border-style is none or border-width is 0.

Constituent properties

This property is a shorthand for the following CSS properties:

Syntax

/* source | slice */
border-image: linear-gradient(red, blue) 27;

/* source | slice | repeat */
border-image: url("/images/border.png") 27 space;

/* source | slice | width */
border-image: linear-gradient(red, blue) 27 / 35px;

/* source | slice | width | outset | repeat */
border-image: url("/images/border.png") 27 23 / 50px 30px / 1rem round space;

/* Global values */
border-image: inherit;
border-image: initial;
border-image: revert;
border-image: unset;

The border-image property may be specified with anywhere from one to five of the values listed below.

Note: If the computed value of border-image-source is none, or if the image cannot be displayed, the border-style will be displayed instead.

Values

<'border-image-source'>

The source image. See border-image-source.

<'border-image-slice'>

The dimensions for slicing the source image into regions. Up to four values may be specified. See border-image-slice.

<'border-image-width'>

The width of the border image. Up to four values may be specified. See border-image-width.

<'border-image-outset'>

The distance of the border image from the element's outside edge. Up to four values may be specified. See border-image-outset.

<'border-image-repeat'>

Defines how the edge regions of the source image are adjusted to fit the dimensions of the border image. Up to two values may be specified. See border-image-repeat.

Accessibility concerns

Assistive technology cannot parse border images. If the image contains information critical to understanding the page's overall purpose, it is better to describe it semantically in the document.

Formal definition

Initial valueas each of the properties of the shorthand:
Applies toall elements, except internal table elements when border-collapse is collapse. It also applies to ::first-letter.
Inheritedno
Percentagesas each of the properties of the shorthand:
Computed valueas each of the properties of the shorthand:
Animation typediscrete

Formal syntax

<'border-image-source'> || <'border-image-slice'> [ / <'border-image-width'> | / <'border-image-width'>? / <'border-image-outset'> ]? || <'border-image-repeat'>

Examples

Bitmap

In this example, we will apply a diamond pattern to an element's borders. The source for the border image is a ".png" file of 81 by 81 pixels, with three diamonds going vertically and horizontally:

an example borderimage

HTML

<div id="bitmap">This element is surrounded by a bitmap-based border image!</div>

CSS

To match the size of a single diamond, we will use a value of 81 divided by 3, or 27, for slicing the image into corner and edge regions. To center the border image on the edge of the element's background, we will make the outset values equal to half of the width values. Finally, a repeat value of round will make the border slices fit evenly, i.e., without clipping or gaps.

#bitmap {
  width: 200px;
  background-color: #ffa;
  border: 36px solid orange;
  margin: 30px;
  padding: 10px;

  border-image:
      url("border.png")  /* source */
      27 /                    /* slice */
      36px 28px 18px 8px /    /* width */
      18px 14px 9px 4px       /* outset */
      round;                  /* repeat */
}

Result

Gradient

HTML

<div id="gradient">This element is surrounded by a gradient-based border image!</div>

CSS

#gradient {
  width: 200px;
  border: 30px solid;
  border-image: repeating-linear-gradient(45deg, #f33, #3bf, #f33 30px) 60;
  padding: 20px;
}

Result

Specifications

Specification
CSS Backgrounds and Borders Module Level 4 (CSS Backgrounds and Borders 4)
# the-border-image

Browser compatibility

BCD tables only load in the browser

See also