Bootstrap 4 vs Bootstrap 5: Key Differences and When to Use Each
Quick Comparison
Here is a quick side-by-side look at the main differences between Bootstrap 4 and Bootstrap 5.
| Feature | Bootstrap 4 | Bootstrap 5 |
|---|---|---|
| jQuery Dependency | Required for JavaScript plugins | Removed, uses vanilla JS |
| Grid System | 12-column with flexbox | Enhanced with gutters and utilities |
| Browser Support | Supports IE10 and IE11 | Drops IE support, modern browsers only |
| Utility API | Limited utility classes | New utility API with CSS variables |
| Forms | Custom form controls | Rebuilt forms with better layout and validation |
| Icons | No built-in icons | Bootstrap Icons introduced separately |
Key Differences
Bootstrap 5 removes the jQuery dependency, making the framework lighter and faster by using plain JavaScript for interactive components. This change simplifies integration with modern JavaScript frameworks and reduces bundle size.
The grid system in Bootstrap 5 is improved with new gutter utilities and responsive containers, allowing more control over spacing and layout. It also introduces CSS custom properties (variables) for colors, spacing, and more, making customization easier without overriding many styles.
Another major difference is browser support: Bootstrap 5 drops support for Internet Explorer, focusing on modern browsers. This allows the use of newer CSS features and cleaner code. Forms are redesigned with better validation styles and layout options. Additionally, Bootstrap 5 introduces a new utility API for easier and more consistent styling, and Bootstrap Icons are provided as a separate official icon set.
Code Comparison
Here is a simple example showing a responsive button with a primary color in Bootstrap 4.
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>Bootstrap 4 Button</title> <link href="https://stackpath.bootstrapcdn.com/bootstrap/4.6.0/css/bootstrap.min.css" rel="stylesheet"> </head> <body> <div class="container mt-3"> <button type="button" class="btn btn-primary">Bootstrap 4 Button</button> </div> <script src="https://code.jquery.com/jquery-3.5.1.slim.min.js"></script> <script src="https://cdn.jsdelivr.net/npm/bootstrap@4.6.0/dist/js/bootstrap.bundle.min.js"></script> </body> </html>
Bootstrap 5 Equivalent
The same button in Bootstrap 5 uses no jQuery and loads updated CSS and JS files.
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>Bootstrap 5 Button</title> <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/css/bootstrap.min.css" rel="stylesheet"> </head> <body> <div class="container mt-3"> <button type="button" class="btn btn-primary">Bootstrap 5 Button</button> </div> <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/js/bootstrap.bundle.min.js"></script> </body> </html>
When to Use Which
Choose Bootstrap 5 if you want a modern, lightweight framework without jQuery, better customization with CSS variables, and support only for modern browsers. It is ideal for new projects aiming for future-proof design and performance.
Choose Bootstrap 4 if you need to support older browsers like Internet Explorer or rely on legacy code that depends on jQuery plugins. It is suitable for maintaining existing projects or when compatibility is a priority.