The border-bottom CSS property is a shorthand that sets the values of border-bottom-width, border-bottom-style and border-bottom-color. These properties describe an element's bottom border.

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. This means that ...

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

... is actually the same as ...

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

... and 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.

Syntax

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

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 syntax

<line-width> || <line-style> || <color>

where
<line-width> = <length> | thin | medium | thick
<line-style> = none | hidden | dotted | dashed | solid | double | groove | ridge | inset | outset
<color> = <rgb()> | <rgba()> | <hsl()> | <hsla()> | <hex-color> | <named-color> | currentcolor | <deprecated-system-color>

where
<rgb()> = rgb( <percentage>{3} [ / <alpha-value> ]? ) | rgb( <number>{3} [ / <alpha-value> ]? ) | rgb( <percentage>#{3} , <alpha-value>? ) | rgb( <number>#{3} , <alpha-value>? )
<rgba()> = rgba( <percentage>{3} [ / <alpha-value> ]? ) | rgba( <number>{3} [ / <alpha-value> ]? ) | rgba( <percentage>#{3} , <alpha-value>? ) | rgba( <number>#{3} , <alpha-value>? )
<hsl()> = hsl( <hue> <percentage> <percentage> [ / <alpha-value> ]? ) | hsl( <hue>, <percentage>, <percentage>, <alpha-value>? )
<hsla()> = hsla( <hue> <percentage> <percentage> [ / <alpha-value> ]? ) | hsla( <hue>, <percentage>, <percentage>, <alpha-value>? )

where
<alpha-value> = <number> | <percentage>
<hue> = <number> | <angle>

Example

<div>
  This box has a border on the bottom side.
</div>
div {
  border-bottom: 4px dashed blue;
  background-color: gold;
  height: 100px;
  width: 100px;
  font-weight: bold;
  text-align: center;
}

Specifications

Specification Status Comment
CSS Backgrounds and Borders Module Level 3
The definition of 'border-bottom' in that specification.
Candidate Recommendation No direct changes, though the modification of values for the border-bottom-color do apply to it.
CSS Level 2 (Revision 1)
The definition of 'border-bottom' in that specification.
Recommendation No significant changes.
CSS Level 1
The definition of 'border-bottom' in that specification.
Recommendation Initial definition.

Initial valueas each of the properties of the shorthand:
Applies toall elements. It also applies to ::first-letter.
Inheritedno
Mediavisual
Computed valueas each of the properties of the shorthand:
Animation typeas each of the properties of the shorthand:
Canonical orderorder of appearance in the formal grammar of the values

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung Internet
Basic supportChrome Full support 1Edge Full support 12Firefox Full support 1IE Full support 4Opera Full support 3.5Safari Full support 1WebView Android Full support 1Chrome Android ? Edge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android ?

Legend

Full support  
Full support
Compatibility unknown  
Compatibility unknown

Document Tags and Contributors

Last updated by: mfuji09,