border-bottom

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

The border-bottom shorthand CSS property sets an element's bottom border. It sets the values of border-bottom-width, border-bottom-style and border-bottom-color.

Try it

As with all shorthand properties, border-bottom always sets the values of all of the properties that it can set, even if they are not specified. It sets those that are not specified to their default values. Consider the following code:

css
border-bottom-style: dotted;
border-bottom: thick green;

It is actually the same as this one:

css
border-bottom-style: dotted;
border-bottom: none thick green;

The value of border-bottom-style given before border-bottom is ignored. Since the default value of border-bottom-style is none, not specifying the border-style part results in no border.

Constituent properties

This property is a shorthand for the following CSS properties:

Syntax

css
border-bottom: 1px;
border-bottom: 2px dotted;
border-bottom: medium dashed blue;

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

The three values of the shorthand property can be specified in any order, and one or two of them may be omitted.

Values

<br-width>

See border-bottom-width.

<br-style>

See border-bottom-style.

<color>

See border-bottom-color.

Formal definition

Initial valueas each of the properties of the shorthand:
Applies toall elements. It also applies to ::first-letter.
Inheritedno
Computed valueas each of the properties of the shorthand:
Animation typeas each of the properties of the shorthand:

Formal syntax

border-bottom = 
  <line-width>  ||
  <line-style>  ||
  <color>       

<line-width> = 
  <length [0,∞]>  |
  thin            |
  medium          |
  thick           

<line-style> = 
  none    |
  hidden  |
  dotted  |
  dashed  |
  solid   |
  double  |
  groove  |
  ridge   |
  inset   |
  outset

Examples

Applying a bottom border

HTML

html
<div>This box has a border on the bottom side.</div>

CSS

css
div {
  border-bottom: 4px dashed blue;
  background-color: gold;
  height: 100px;
  width: 100px;
  font-weight: bold;
  text-align: center;
}

Results

Specifications

Specification
CSS Backgrounds and Borders Module Level 3
# border-shorthands

Browser compatibility

BCD tables only load in the browser

See also