Customization options

Customize Bootstrap 4 with our built-in custom variables file and easily toggle global CSS preferences with new $enable-* Sass variables. Override a variable’s value and recompile with the included Gruntfile as needed.

Customizing variables

Bootstrap 4 ships with a _custom.scss file for easy variable overrides. Copy and paste relevant lines from _variables.scss into the custom file and recompile your Sass to change our default values. Be sure to remove the !default flag from override values.

For example, to change out the background-color and color for the <body>, you’d do the following:

// Bootstrap overrides
//
// Copy variables from `_variables.scss` to this file to override default values
// without modifying source files.

$body-bg:    $gray-dark;
$body-color: $gray-light;

Do the same for any variable you need to override, including the global options listed below.

Global options

You can find and customize these variables for key global options in our _variables.scss file.

Variable Values Description
$spacer 1rem (default), or any value > 0 Specifies the default spacer value for our spacer utilities.
$enable-flex true or false (default) Swaps float and display: table styles for display: flex.
$enable-rounded true (default) or false Enables predefined border-radius styles on various components.
$enable-shadows true or false (default) Enables predefined box-shadow styles on various components.
$enable-gradients true or false (default) Enables predefined gradients via background-image styles on various components.
$enable-transitions true (default) or false Enables predefined transitions on various components.
$enable-hover-media-query true or false (default)
$enable-grid-classes true (default) or false Enables the generation of CSS classes for the grid system (e.g., .container, .row, .col-md-1, etc.).