box-decoration-break

This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for the proper prefixes to use in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the spec changes.

The box-decoration-break CSS property specifies how the background, padding, border, border-image, box-shadow, margin and clip of an element is applied when the box for the element is fragmented.  Fragmentation occurs when an inline box wraps onto multiple lines, or when a block spans more than one column inside a column layout container, or spans a page break when printed.  Each piece of the rendering for the element is called a fragment.

Syntax

box-decoration-break: slice;
box-decoration-break: clone;

box-decoration-break: initial;
box-decoration-break: inherit;
box-decoration-break: unset;

Values

slice
The element is rendered as if its box were not fragmented, and then the rendering for this hypothetical box is sliced into pieces for each line/column/page. Note that the hypothetical box can be different for each fragment since it uses its own height if the break occurs in the inline direction, and its own width if the break occurs in the block direction. See the CSS specification for details.
clone
Each box fragment is rendered independently with the specified border, padding and margin wrapping each fragment. The border-radius, border-image and box-shadow, are applied to each fragment independently. The background is drawn independently in each fragment which means that a background image with background-repeat: no-repeat may be repeated multiple times.

Formal syntax

slice | clone

Examples

Inline box fragments

An inline element that contains line-breaks styled with:

.example { 
  background: linear-gradient(to bottom right, yellow, green);
  box-shadow:
    8px 8px 10px 0px deeppink, 
    -5px -5px 5px 0px blue, 
    5px 5px 15px 0px yellow;
  padding: 0em 1em;
  border-radius: 16px;
  border-style: solid;
  margin-left: 10px;
  font: 24px sans-serif;
  line-height: 2;
}

...
<span class="example">The<br>quick<br>orange fox</span>

Results in:

A screenshot of the rendering of an inline element styled with box-decoration-break:slice and styles given in the example.

Adding box-decoration-break:clone to the above styles:

  -webkit-box-decoration-break: clone;
  -o-box-decoration-break: clone;
  box-decoration-break: clone;

Results in:

A screenshot of the rendering of an inline element styled with box-decoration-break:clone and styles given in the example

You can try the two inline examples above in your browser.

Here's an example of an inline element using a large border-radius value. The second "iM" has a line-break between the "i" and the "M". For comparison, the first "iM" is without line-breaks. Note that if you stack the rendering of the two fragments horizontally next to each other it will result in the non-fragmented rendering.

A screenshot of the rendering of the second inline element example.

Try the above example in your browser.

Block box fragments

A block element with similar styles as above, first without any fragmentation:

A screenshot of the rendering of the block element used in the examples without any fragmentation.

Fragmenting the above block into three columns results in:

A screenshot of the rendering of the fragmented block used in the examples styled with box-decoration-break:slice.

Note that stacking these pieces vertically will result in the non-fragmented rendering.

Now the same example styled with box-decoration-break:clone

A screenshot of the rendering of the fragmented block used in the examples styled with box-decoration-break:clone.

Note here that each fragment has an identical replicated border, box-shadow and background.

You can try the block examples above in your browser.

Specifications

Specification Status Comment
CSS Fragmentation Module Level 3
The definition of 'box-decoration-break' in that specification.
Working Draft Initial definition

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Support on inline elements (Yes)-webkit 32.0 (32.0) [1] ? (Yes)-o ?
Support on non-inline element Not supported 32.0 (32.0) [1] ? ? Not supported
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Support on inline elements ? ? 32.0 (32.0) ? ? ?
Support on non-inline element Not supported Not supported 32.0 (32.0) ? ? Not supported

[1] Note that Firefox implemented an non-standard version of this property before Firefox 32 named -moz-background-inline-policy. That property is unsupported since Firefox 32.

See also

Document Tags and Contributors

Contributors to this page: fscholz, Sebastianz, teoli, Mats.Palmgren, jonathansampson, ntim007
Last updated by: fscholz,