CSS border-bottom-width Attribute

Definition and usage

The borderBottomWidth property sets the width of the bottom border of the element.

This property only takes effect when the border style is not none. If the border style is none, the border width is actually reset to 0. Negative length values are not allowed.

Note:Always declare the border-style property before the border-bottom-width property. The element must have a border before its border width can be changed.

See also:

CSS Tutorial:CSS Borders

CSS Reference Manual:border-bottom property

HTML DOM Reference Manual:borderBottomWidth property

Example

Set bottom border width:

p
  {
  border-style:solid;
  border-bottom-width:15px;
  }

Try it yourself

CSS syntax

border-bottom-width: medium|thin|thick|length|initial|inherit;

Property value

Value Description
thin Define a thin bottom border.
medium Default value. Defines a medium bottom border.
thick Define a thick bottom border.
length Allows you to customize the width of the bottom border.
inherit Specify that the border width should be inherited from the parent element.

More examples

Set bottom border width
This example demonstrates how to set the width of the bottom border.

Technical details

Default value: medium
Inheritance: no
Version: CSS1
JavaScript syntax: object.style.borderBottomWidth="thick"

Browser support

The numbers in the table indicate the first browser version that fully supports this property.

Chrome IE / Edge Firefox Safari Opera
1.0 4.0 1.0 1.0 3.5

Note:Browsers with IE7 and earlier versions do not support the value "inherit". IE8 requires !DOCTYPE. IE9 supports "inherit".