description: Quickly customize Bootstrap with built-in variables to easily toggle global CSS preferences for controlling style and behavior.
group: customize
---
Customize Bootstrap with our built-in custom variables file and easily toggle global CSS preferences with new `$enable-*` Sass variables. Override a variable's value and recompile with `npm run test` as needed.
You can find and customize these variables for key global options in Bootstrap's `scss/_variables.scss` file.
| `$spacer` | `1rem` (default), or any value > 0 | Specifies the default spacer value to programmatically generate our [spacer utilities]({{< docsref "/utilities/spacing" >}}). |
| `$enable-rounded` | `true` (default) or `false` | Enables predefined `border-radius` styles on various components. |
| `$enable-shadows` | `true` or `false` (default) | Enables predefined decorative `box-shadow` styles on various components. Does not affect `box-shadow`s used for focus states. |
| `$enable-gradients` | `true` or `false` (default) | Enables predefined gradients via `background-image` styles on various components. |
| `$enable-transitions` | `true` (default) or `false` | Enables predefined `transition`s on various components. |
| `$enable-reduced-motion` | `true` (default) or `false` | Enables the [`prefers-reduced-motion` media query]({{< docsref "/getting-started/accessibility#reduced-motion" >}}), which suppresses certain animations/transitions based on the users' browser/operating system preferences. |
| `$enable-grid-classes` | `true` (default) or `false` | Enables the generation of CSS classes for the grid system (e.g. `.row`, `.col-md-1`, etc.). |
| `$enable-caret` | `true` (default) or `false` | Enables pseudo element caret on `.dropdown-toggle`. |
| `$enable-button-pointers` | `true` (default) or `false` | Add "hand" cursor to non-disabled button elements. |
| `$enable-validation-icons` | `true` (default) or `false` | Enables `background-image` icons within textual inputs and some custom forms for validation states. |
| `$enable-deprecation-messages` | `true` (default) or `false` | Set to `false` to hide warnings when using any of the deprecated mixins and functions that are planned to be removed in `v6`. |