---
title: "What is the role of CSS custom properties in Bootstrap 5?"  
description: "What is the role of CSS custom properties in Bootstrap 5?"  
author: "Utpal Vishwas"  
published: 2023-04-23  
updated: 2023-11-21  
canonical: https://www.mindstick.com/forum/157966/what-is-the-role-of-css-custom-properties-in-bootstrap-5  
category: "bootstrap"  
tags: ["bootstrap", "bootstrap 5"]  
reading_time: 3 minutes  

---

# What is the role of CSS custom properties in Bootstrap 5?

What is the [role](https://yourviews.mindstick.com/audio/1254/the-role-of-visualization-in-achieving-your-goals) of [CSS custom](https://www.mindstick.com/forum/160673/css-custom-properties-variables-vs-preprocessor-variables) [properties](https://www.mindstick.com/articles/23331/nootropics-7-different-types-and-their-unique-properties) in [Bootstrap](https://www.mindstick.com/articles/1555/image-viewer-using-bootstrap-carousel) 5?

## Replies

### Reply by Aryan Kumar

As of my last knowledge update in January 2022, Bootstrap 5 introduced the use of [CSS](https://www.mindstick.com/forum/514/background-gradient-ie7-css-problem) [custom](https://www.mindstick.com/blog/12298/use-custom-writing-services-to-get-through-the-finals) properties (also known as CSS variables) to enhance customization and theming capabilities. Custom properties play a significant role in Bootstrap 5 by allowing developers to easily customize the default styling of components using variables. Here's how CSS custom properties are used in Bootstrap 5:

### 1. Theming and Customization:

- CSS custom properties enable theming and customization by defining variables for commonly used values such as colors, spacing, fonts, and more. This makes it easier for developers to create a consistent and customized look and feel across their Bootstrap-based projects.

### 2. Global Theming Variables:

- Bootstrap 5 defines a set of global theming variables using CSS custom properties. These variables are used throughout the framework to control the appearance of various components. Examples of global theming variables include:

   - **--bs-primary**, **--bs-secondary**: Colors for primary and secondary elements.
   - **--bs-success**, **--bs-info**, **--bs-warning**, **--bs-danger**: Colors for contextual alert messages.
   - **--bs-font-family-base**: Base font family used in the framework.
   - **--bs-spacing**: Base spacing unit.

### 3. Custom Properties in Components:

- Bootstrap 5 components often use these custom properties to define their default styles. For example, the **background-color** of a button might be set using the **var(--bs-primary)** custom property.

### 4. Customization at Scale:

- By leveraging CSS custom properties, Bootstrap allows developers to customize the entire theme at scale by simply updating a set of global variables. This makes it easier to maintain consistency and make widespread changes without modifying each individual component.

### 5. Responsive Breakpoints:

- Bootstrap 5 uses custom properties for defining responsive breakpoints, allowing developers to customize these breakpoints based on project requirements.

### 6. Utility Classes:

- CSS custom properties are often utilized in utility classes to provide flexibility in styling. For instance, spacing utilities may use custom properties to define the default spacing unit.

### 7. Customization Example:

- Developers can override the default theming variables in their projects to create a customized theme. For example:

```plaintext
:root {
  --bs-primary: #ff0000; /* Red color as the primary color */
  --bs-secondary: #00ff00; /* Green color as the secondary color */
}
```

### Important Note:

As of my last knowledge update, Bootstrap 5 continued to evolve, and there may have been further updates or changes to the framework. It's always recommended to check the official Bootstrap documentation and release notes for the most current information on the use of CSS custom properties in Bootstrap 5.


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Original Source: https://www.mindstick.com/forum/157966/what-is-the-role-of-css-custom-properties-in-bootstrap-5

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