Customize the native <select>s with custom CSS that changes the element’s initial appearance.

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Default

Custom <select> menus need only a custom class, .form-select to trigger the custom styles. Custom styles are limited to the <select>’s initial appearance and cannot modify the <option>s due to browser limitations.

html
<select class="form-select" aria-label="Default select example">
  <option selected>Open this select menu</option>
  <option value="1">One</option>
  <option value="2">Two</option>
  <option value="3">Three</option>
</select>

Sizing

You may also choose from small and large custom selects to match our similarly sized text inputs.

html
<select class="form-select form-select-lg mb-3" aria-label="Large select example">
  <option selected>Open this select menu</option>
  <option value="1">One</option>
  <option value="2">Two</option>
  <option value="3">Three</option>
</select>

<select class="form-select form-select-sm" aria-label="Small select example">
  <option selected>Open this select menu</option>
  <option value="1">One</option>
  <option value="2">Two</option>
  <option value="3">Three</option>
</select>

The multiple attribute is also supported:

html
<select class="form-select" multiple aria-label="Multiple select example">
  <option selected>Open this select menu</option>
  <option value="1">One</option>
  <option value="2">Two</option>
  <option value="3">Three</option>
</select>

As is the size attribute:

html
<select class="form-select" size="3" aria-label="Size 3 select example">
  <option selected>Open this select menu</option>
  <option value="1">One</option>
  <option value="2">Two</option>
  <option value="3">Three</option>
</select>

Disabled

Add the disabled boolean attribute on a select to give it a grayed out appearance and remove pointer events.

html
<select class="form-select" aria-label="Disabled select example" disabled>
  <option selected>Open this select menu</option>
  <option value="1">One</option>
  <option value="2">Two</option>
  <option value="3">Three</option>
</select>

CSS

Sass variables

$form-select-padding-y:             $input-padding-y;
$form-select-padding-x:             $input-padding-x;
$form-select-font-family:           $input-font-family;
$form-select-font-size:             $input-font-size;
$form-select-indicator-padding:     $form-select-padding-x * 3; // Extra padding for background-image
$form-select-font-weight:           $input-font-weight;
$form-select-line-height:           $input-line-height;
$form-select-color:                 $input-color;
$form-select-bg:                    $input-bg;
$form-select-disabled-color:        $input-disabled-color; // Boosted mod: instead of `null`
$form-select-disabled-bg:           $input-disabled-bg;
$form-select-disabled-border-color: $input-disabled-border-color;
$form-select-bg-position:           right $form-select-padding-x top add(50%, 1px);
$form-select-bg-size:               .875rem 1rem; // In pixels because image dimensions
$form-select-indicator:             escape-svg(url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 14 7'><path d='M7 7 0 0h14L7 7z'/></svg>")); // Boosted mod: instead of Bootstrap svg
$form-select-disabled-indicator:    escape-svg(url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 14 7'><path fill='#{$gray-700}' d='M7 7 0 0h14L7 7z'/></svg>")); // Boosted mod

$form-select-feedback-icon-padding-end: $form-select-padding-x * 2.5 + $form-select-indicator-padding;
$form-select-feedback-icon-position:    center right $form-select-indicator-padding;
$form-select-feedback-icon-size:        $input-height-inner-half $input-height-inner-half;

$form-select-border-width:        $input-border-width;
$form-select-border-color:        $input-border-color;
$form-select-border-radius:       $input-border-radius;
$form-select-box-shadow:          none; // Boosted mod

$form-select-focus-border-color:  $input-color; // Boosted mod: handle a Firefox-specific visible focus rendering where we remove the border from the select box (see `.form-select` rule)
// Boosted mod: no $form-select-focus-width
$form-select-focus-box-shadow:    none; // Boosted mod

$form-select-padding-y-sm:        add($input-padding-y-sm, 1px); // Boosted mod
$form-select-padding-x-sm:        $input-padding-x-sm;
$form-select-font-size-sm:        $input-font-size-sm;
$form-select-border-radius-sm:    $input-border-radius-sm;

$form-select-padding-y-lg:        $spacer * .5; // Boosted mod
$form-select-padding-x-lg:        $input-padding-x-lg;
$form-select-font-size-lg:        $input-font-size-lg;
$form-select-border-radius-lg:    $input-border-radius-lg;

$form-select-transition:          $input-transition;