How to customize the Bootstrap theme

How to customize the Bootstrap theme

Bootstrap is one of the most popular front-end frameworks for building responsive and visually appealing websites. Its pre-designed templates and components make it easy for developers to create stunning web applications. However, using the default Bootstrap theme can make your website look generic and lack a distinct identity. To stand out from the crowd and tailor your site to match your brand or project, customizing the Bootstrap theme is the way to go. In this blog post, we’ll walk you through the steps to customize the Bootstrap theme and make your website truly unique.

Step 1: Understanding Bootstrap’s Theming Structure

Before you start customizing, it’s essential to understand Bootstrap’s theming structure. Bootstrap uses Sass, a powerful CSS preprocessor, to manage its styles. To customize the theme, you will work with Sass variables and override the default styles. This enables you to change colors, fonts, spacing, and other aspects to match your design requirements.

Step 2: Setting up Your Project

To get started, create a new project or open your existing Bootstrap-based project. Ensure you have Bootstrap installed via npm or include the Bootstrap CSS and JavaScript files in your HTML.

Step 3: Customizing Colors

One of the primary ways to customize the Bootstrap theme is by changing colors. Bootstrap uses a set of color variables, and by overriding these variables, you can give your website a unique color scheme. Open your main Sass file (usually named styles.scss or similar) and define your custom color variables. For example:

$primary-color: #FF5733;
$secondary-color: #0088FF;

Update these variables with the desired colors. You can also change other color-related variables, such as $success, $warning, $danger, etc. Once you’ve made your changes, compile your Sass file into CSS, and your new color scheme will take effect.

Step 4: Typography Customization

Typography plays a significant role in website design. Bootstrap provides several font-related variables to customize the typography. To change the font family, size, or line height, update the relevant Sass variables. For instance:

$body-font-family: 'Arial', sans-serif;
$h1-font-size: 3rem;
$p-line-height: 1.6;

Tweak these variables to match your desired typography. Don’t forget to recompile your Sass to see the changes.

Step 5: Spacing and Layout

To fine-tune spacing and layout, Bootstrap offers a range of spacing variables. These variables define the padding and margin sizes for various components and elements. By modifying these variables, you can adjust the spacing between elements and create a better visual hierarchy. For example:

$spacer: 1.5rem;
$button-padding-x: 1.5rem;
$button-padding-y: 0.75rem;

Play around with these values until you achieve the desired spacing and layout for your website.

Step 6: Customizing Components

Bootstrap comes with a plethora of components, such as buttons, cards, navbars, and more. To customize the appearance of these components, you can override their default styles using CSS classes. For example, let’s customize the button component:

.btn {
  border-radius: 20px;
  text-transform: uppercase;

This will apply the specified styles to all buttons on your website. You can also target specific buttons using additional class selectors or IDs.

Step 7: Handling Responsiveness

Bootstrap is renowned for its responsive design capabilities. While customizing, ensure that your changes don’t break the responsive layout. Test your website on different screen sizes and devices to ensure everything looks great across the board.

Step 8: Using Custom CSS

While Sass variables offer substantial customization options, you may still need to write custom CSS to achieve certain design elements. You can create a separate CSS file and include it in your project to hold the additional styles. However, be mindful not to override Bootstrap’s core styles too much, as it might lead to maintenance issues in the future.


Customizing the Bootstrap theme allows you to give your website a unique identity and align it with your brand or project’s vision. By leveraging Sass variables, you can easily modify colors, typography, spacing, and other design elements to create a visually stunning website. Remember to maintain responsiveness and use custom CSS judiciously. Now, armed with these customization techniques, go ahead and build a website that truly stands out in the crowded digital landscape! Happy theming!