Use border utilities to quickly style the border and border-radius of an element. Great for images, buttons, or any other element.

Border

Use border utilities to add or remove an element’s borders. Choose from all borders or one at a time.

Additive

Add borders to custom elements:

html
<span class="border"></span>
<span class="border-top"></span>
<span class="border-end"></span>
<span class="border-bottom"></span>
<span class="border-start"></span>

Subtractive

Or remove borders:

html
<span class="border border-0"></span>
<span class="border border-top-0"></span>
<span class="border border-end-0"></span>
<span class="border border-bottom-0"></span>
<span class="border border-start-0"></span>

Color

Change the border color using utilities built on our theme colors.

html
<span class="border border-primary"></span>
<span class="border border-secondary"></span>
<span class="border border-success"></span>
<span class="border border-danger"></span>
<span class="border border-warning"></span>
<span class="border border-info"></span>
<span class="border border-light"></span>
<span class="border border-dark"></span>
<span class="border border-white"></span>

Or modify the default border-color of a component:

Dangerous heading
Changing border color and width
html
<div class="mb-4">
  <label for="exampleFormControlInput1" class="form-label">Email address</label>
  <input type="email" class="form-control border-success" id="exampleFormControlInput1" placeholder="name@example.com">
</div>

<div class="h4 pb-2 mb-4 text-danger border-bottom border-danger">
  Dangerous heading
</div>

<div class="p-3 bg-info bg-opacity-10 border border-info border-start-0 rounded-end">
  Changing border color and width
</div>

Opacity

Added in v5.2.0

Boosted border-{color} utilities are generated with Sass using CSS variables. This allows for real-time color changes without compilation and dynamic alpha transparency changes.

How it works

Consider our default .border-success utility.

.border-success {
  --bs-border-opacity: 1;
  border-color: rgba(var(--bs-success-rgb), var(--bs-border-opacity)) !important;
}

We use an RGB version of our --bs-success (with the value of 25, 135, 84) CSS variable and attached a second CSS variable, --bs-border-opacity, for the alpha transparency (with a default value 1 thanks to a local CSS variable). That means anytime you use .border-success now, your computed color value is rgba(25, 135, 84, 1). The local CSS variable inside each .border-* class avoids inheritance issues so nested instances of the utilities don’t automatically have a modified alpha transparency.

Example

To change that opacity, override --bs-border-opacity via custom styles or inline styles.

This is default success border
This is 50% opacity success border
html
<div class="border border-success p-2 mb-2">This is default success border</div>
<div class="border border-success p-2" style="--bs-border-opacity: .5;">This is 50% opacity success border</div>

Or, choose from any of the .border-opacity utilities:

This is default success border
This is 75% opacity success border
This is 50% opacity success border
This is 25% opacity success border
This is 10% opacity success border
html
<div class="border border-success p-2 mb-2">This is default success border</div>
<div class="border border-success p-2 mb-2 border-opacity-75">This is 75% opacity success border</div>
<div class="border border-success p-2 mb-2 border-opacity-50">This is 50% opacity success border</div>
<div class="border border-success p-2 mb-2 border-opacity-25">This is 25% opacity success border</div>
<div class="border border-success p-2 border-opacity-10">This is 10% opacity success border</div>

Width

html
<span class="border border-0"></span>
<span class="border border-1"></span>
<span class="border border-2"></span>
<span class="border border-3"></span>

Radius

Add classes to an element to easily round its corners.

Example rounded image75x75 Rounded pill image150x75
html
<img src="..." class="rounded-circle" alt="...">
<img src="..." class="rounded-pill" alt="...">

Dividers





html
<div class="bg-dark p-1">
  <div class="border-top border-white my-3"></div>
  <hr>
</div>
<div class="border-top border-light my-3"></div>
<div class="border-top border-light border-1 my-3"></div>
<div class="border-top border-dark my-3"></div>
<div class="border-top border-dark border-1 my-3"></div>
<div class="border-top my-3"></div>
<hr class="text-light">
<hr class="text-muted">
<hr>

CSS

Variables

  --#{$prefix}border-width: #{$border-width};
  --#{$prefix}border-style: #{$border-style};
  --#{$prefix}border-color: #{$border-color};
  --#{$prefix}border-color-translucent: #{$border-color-translucent};

  --#{$prefix}border-radius: #{$border-radius};
  --#{$prefix}border-radius-sm: #{$border-radius-sm};
  --#{$prefix}border-radius-lg: #{$border-radius-lg};
  --#{$prefix}border-radius-xl: #{$border-radius-xl};
  --#{$prefix}border-radius-2xl: #{$border-radius-2xl};
  --#{$prefix}border-radius-pill: #{$border-radius-pill};
  

Sass variables

$border-width:                .125rem;
$border-widths: (
  1: $border-width * .5,
  2: $border-width,
  3: $border-width * 1.5
);

$border-style:                solid;
$border-color:                $black; // Boosted mod
$border-color-translucent:    $gray-500; // Boosted mod: gray value instead of rgba($black, .175)
// Boosted mod: all `$border-radius*` values are `null`
$border-radius:               null;
$border-radius-sm:            null;
$border-radius-lg:            null;
$border-radius-xl:            null;
$border-radius-2xl:           null;
// End mod
$border-radius-pill:          50rem;

Sass mixins

@mixin border-radius($radius: $border-radius, $fallback-border-radius: false) {
  @if $enable-rounded {
    border-radius: valid-radius($radius);
  }
  @else if $fallback-border-radius != false {
    border-radius: $fallback-border-radius;
  }
}

@mixin border-top-radius($radius: $border-radius) {
  @if $enable-rounded {
    border-top-left-radius: valid-radius($radius);
    border-top-right-radius: valid-radius($radius);
  }
}

@mixin border-end-radius($radius: $border-radius) {
  @if $enable-rounded {
    border-top-right-radius: valid-radius($radius);
    border-bottom-right-radius: valid-radius($radius);
  }
}

@mixin border-bottom-radius($radius: $border-radius) {
  @if $enable-rounded {
    border-bottom-right-radius: valid-radius($radius);
    border-bottom-left-radius: valid-radius($radius);
  }
}

@mixin border-start-radius($radius: $border-radius) {
  @if $enable-rounded {
    border-top-left-radius: valid-radius($radius);
    border-bottom-left-radius: valid-radius($radius);
  }
}

@mixin border-top-start-radius($radius: $border-radius) {
  @if $enable-rounded {
    border-top-left-radius: valid-radius($radius);
  }
}

@mixin border-top-end-radius($radius: $border-radius) {
  @if $enable-rounded {
    border-top-right-radius: valid-radius($radius);
  }
}

@mixin border-bottom-end-radius($radius: $border-radius) {
  @if $enable-rounded {
    border-bottom-right-radius: valid-radius($radius);
  }
}

@mixin border-bottom-start-radius($radius: $border-radius) {
  @if $enable-rounded {
    border-bottom-left-radius: valid-radius($radius);
  }
}

Utilities API

Border utilities are declared in our utilities API in scss/_utilities.scss. Learn how to use the utilities API.

    "border": (
      property: border,
      values: (
        null: var(--#{$prefix}border-width) var(--#{$prefix}border-style) var(--#{$prefix}border-color),
        0: 0,
      )
    ),
    "border-top": (
      property: border-top,
      values: (
        null: var(--#{$prefix}border-width) var(--#{$prefix}border-style) var(--#{$prefix}border-color),
        0: 0,
      )
    ),
    "border-end": (
      property: border-right,
      class: border-end,
      values: (
        null: var(--#{$prefix}border-width) var(--#{$prefix}border-style) var(--#{$prefix}border-color),
        0: 0,
      )
    ),
    "border-bottom": (
      property: border-bottom,
      values: (
        null: var(--#{$prefix}border-width) var(--#{$prefix}border-style) var(--#{$prefix}border-color),
        0: 0,
      )
    ),
    "border-start": (
      property: border-left,
      class: border-start,
      values: (
        null: var(--#{$prefix}border-width) var(--#{$prefix}border-style) var(--#{$prefix}border-color),
        0: 0,
      )
    ),
    "border-color": (
      property: border-color,
      class: border,
      local-vars: (
        "border-opacity": 1
      ),
      values: $utilities-border-colors
    ),
    "border-width": (
      css-var: true,
      css-variable-name: border-width,
      class: border,
      values: $border-widths
    ),
    "border-opacity": (
      css-var: true,
      class: border-opacity,
      values: (
        10: .1,
        25: .25,
        50: .5,
        75: .75,
        100: 1
      )
    ),
    
    "rounded": (
      property: border-radius,
      class: rounded,
      values: (
        null: var(--#{$prefix}border-radius),
        0: 0,
        1: var(--#{$prefix}border-radius-sm),
        2: var(--#{$prefix}border-radius),
        3: var(--#{$prefix}border-radius-lg),
        4: var(--#{$prefix}border-radius-xl),
        5: var(--#{$prefix}border-radius-2xl),
        circle: 50%,
        pill: var(--#{$prefix}border-radius-pill)
      )
    ),
    "rounded-top": (
      property: border-top-left-radius border-top-right-radius,
      class: rounded-top,
      values: (null: var(--#{$prefix}border-radius))
    ),
    "rounded-end": (
      property: border-top-right-radius border-bottom-right-radius,
      class: rounded-end,
      values: (null: var(--#{$prefix}border-radius))
    ),
    "rounded-bottom": (
      property: border-bottom-right-radius border-bottom-left-radius,
      class: rounded-bottom,
      values: (null: var(--#{$prefix}border-radius))
    ),
    "rounded-start": (
      property: border-bottom-left-radius border-top-left-radius,
      class: rounded-start,
      values: (null: var(--#{$prefix}border-radius))
    ),