box-decoration-break

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.

Initial value	slice
Applies to	all elements
Inherited	no
Media	visual
Computed value	as specified
Animation type	discrete
Canonical order	the unique non-ambiguous order defined by the formal grammar

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:

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:

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.

Try the above example in your browser.

Block box fragments

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

Fragmenting the above block into three columns results in:

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

Now the same example 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.	Candidate Recommendation	Initial definition

Browser compatibility

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

See also

• CSS Reference