border-bottom-width | CSS CSS Properties

Controls the thickness of the bottom border. It is frequently paired with a specific color to create focus indicators or status bars.

Quick example

.notification-banner {
  background: #f0f9ff;
  /* Adds a subtle 1px line at the very bottom */
  border-bottom-width: 1px;
  border-bottom-style: solid;
  border-bottom-color: #bae6fd;
}

Quick facts

Initial value

medium

Inherited

Applies to

all elements

Animation type

length

border-bottom-width Browser Support

Widely available Since 2015 96% global usage

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

Safe to use without fallbacks.

View on caniuse.com → View on MDN → View on webstatus.dev → Learn more about Baseline →

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