Bootstrap Versions

Bootstrap is one of the most influential front-end frameworks in modern web development. Since its introduction in 2011, it has shaped how designers and developers build responsive, mobile-first websites with speed and consistency. Over the years, Bootstrap has gone through major transformations—each version bringing new features, improvements, and philosophies that reflect the evolving landscape of the web.

Today, Bootstrap 5 is the most widely used version, celebrated for removing the jQuery dependency, modernizing components, introducing utility APIs, and providing more freedom and customization. But to truly appreciate Bootstrap 5, it helps to understand how Bootstrap evolved through versions 1, 2, 3, and 4 before landing where it is today.

This long-form article explores Bootstrap’s versions in depth—its history, evolution, major updates, comparisons, and the reasons Bootstrap 5 dominates the ecosystem today.

1. Introduction to Bootstrap

Bootstrap is an open-source CSS framework originally developed at Twitter by Mark Otto and Jacob Thornton. The goal was simple: create a standardized design toolkit so that internal projects did not need to reinvent UI components repeatedly. Their work became one of the most loved frameworks in the world, helping millions of developers build websites faster and more efficiently.

Bootstrap offers:

A responsive grid system
Pre-designed UI components
JavaScript plugins
Utility classes
Themes and customization options
Strong documentation

Its philosophy since the beginning has been consistency, ease of use, and rapid development.

2. The Early Days: Bootstrap 1

Released in 2011, Bootstrap 1 marked the beginning of a revolution in web design.

2.1 Key Features of Bootstrap 1

Bootstrap 1 introduced a standardized design language with:

The first version of the grid system
Basic typography styles
Early components such as buttons, forms, alerts
Scaffolding for responsive layouts (though limited)

Users could quickly apply classes and get consistent visuals without writing CSS from scratch.

2.2 Limitations of Bootstrap 1

Although groundbreaking, it lacked:

A fully responsive layout system
Mobile-first design
Flexibility for customization

These limitations were addressed in future versions.

3. Bootstrap 2: The Beginning of Responsive Design

In 2012, Bootstrap 2 significantly expanded the framework.

3.1 Introduction of Responsive Features

Bootstrap 2 marked the first time the framework supported:

A responsive grid
Responsive utility classes
Fluid layouts

This version was released around the time mobile use was growing rapidly, making it timely and valuable.

3.2 Expanded Component Library

Bootstrap 2 added many essential components:

Navbars
Dropdowns
Breadcrumbs
Media objects
Progress bars

The UI toolkit became richer and more usable for larger projects.

4. Bootstrap 3: The Mobile-First Revolution

In 2013, Bootstrap 3 introduced a major shift toward mobile-first design—a philosophy where layouts are designed for small devices first, then scaled up.

4.1 Mobile-First Grid System

The grid became more refined with breakpoints such as:

Developers could now display different content on different devices with ease.

4.2 Flat Design Aesthetic

Bootstrap 3 adopted the flat design trend of the time, reducing shadows and gradients. This modern look made it widely appealing.

4.3 More Components and Utilities

Bootstrap 3 expanded on:

Panels
Wells
Glyphicons
Improved forms and navigation

It quickly became the default choice for developers and remained dominant for years.

4.4 Widespread Adoption

Many corporate websites, startups, universities, and SaaS platforms used Bootstrap 3. It became nearly synonymous with responsive design.

5. Bootstrap 4: A Modern and Powerful Framework

Released in 2018 (after a long beta phase), Bootstrap 4 was a massive upgrade.

5.1 Moving to Flexbox

Bootstrap 4 replaced the float-based layout with Flexbox, bringing:

Better alignment
More control over responsiveness
Easier layout manipulation

Flexbox made the grid much more powerful and modern.

5.2 Sass Instead of Less

The framework transitioned from Less to Sass, improving:

Variables
Mixins
Nested rules
Customization flexibility

This aligned Bootstrap with modern CSS workflows.

5.3 New Components

Bootstrap 4 introduced or improved:

Cards (replacing panels and wells)
Updated forms
Better utilities
Enhanced navbar

The card component became especially popular.

5.4 Redesigned Grid System

New grid concepts included:

xl breakpoint
Reboot CSS
Updated container rules

Bootstrap 4 became more scalable and enterprise-ready.

5.5 Still Dependent on jQuery

One drawback was the continued dependency on jQuery for JavaScript components. As the web moved toward vanilla JavaScript and frameworks like React, this dependency felt outdated.

6. Bootstrap 5: The Modern Standard

Released in 2021, Bootstrap 5 is the version most widely used today. It is a modern, flexible, and powerful framework that reflects current web standards.

6.1 Removal of jQuery Dependency

Perhaps the biggest change:

No more jQuery
Pure ES6 JavaScript

This made Bootstrap lighter, faster, and more compatible with JS frameworks.

6.2 Updated Design Language

Bootstrap 5 refined its visual style with:

New color palettes
Larger utilities
Better accessibility
Updated forms

The design feels more modern and minimalistic.

6.3 Introduction of Utility API

Bootstrap 5 introduced a Utility API that makes it easy to:

Generate custom utility classes
Reduce custom CSS
Simplify responsive design

This shift brings Bootstrap closer to utility-first frameworks.

6.4 New and Improved Components

Bootstrap 5 added new features such as:

Offcanvas components
Upgraded navbar
Revamped forms
Accordion replacing card collapse patterns

The components are cleaner and more flexible.

6.5 Dropping Support for Older Browsers

Bootstrap 5 focuses on modern browsers, enabling the use of:

CSS custom properties
Modern layout techniques
Advanced selectors

This decision keeps Bootstrap aligned with the future of the web.

7. Comparing All Bootstrap Versions

This section summarizes how each version evolved.

7.1 Bootstrap 1 vs Bootstrap 2

Bootstrap 1 established the foundation
Bootstrap 2 introduced responsiveness

7.2 Bootstrap 2 vs Bootstrap 3

Bootstrap 3 was mobile-first
Bootstrap 2 was responsive but not mobile-first

7.3 Bootstrap 3 vs Bootstrap 4

Bootstrap 4 switched to Flexbox
Bootstrap 3 used floats

7.4 Bootstrap 4 vs Bootstrap 5

Bootstrap 5 removed jQuery
Bootstrap 5 added utility APIs
Bootstrap 5 improved design and accessibility

7.5 Evolution Summary

The framework evolved from:

Basic → Responsive → Mobile-first → Flexbox → Modern JS and utilities

8. Why Bootstrap 5 Is the Most Widely Used Version Today

There are several clear reasons why developers prefer Bootstrap 5.

8.1 Modern JavaScript Without jQuery

Removing jQuery has made Bootstrap:

Faster
Lighter
More compatible with SPA frameworks

8.2 Cleaner and More Minimal Design

The visuals are more modern, neutral, and customizable.

8.3 Better Developer Experience

The Utility API, improved grid, and new components make development faster.

8.4 Strong Documentation

Bootstrap continues to excel in documentation quality.

8.5 Active Community

Bootstrap 5 is actively maintained with continuous updates.

9. Real-World Adoption of Bootstrap 5

Bootstrap 5 is widely used in:

Corporate websites
Admin dashboards
Ecommerce front-ends
Blogs and portfolios
Educational platforms
SaaS interfaces

Its combination of speed and stability makes it attractive for both small and large projects.

10. Should You Still Use Older Versions?

Some legacy projects still rely on older versions such as Bootstrap 3 or 4.

10.1 When Bootstrap 3 Is Still Used

Older enterprise systems
Websites created before 2018
Projects where upgrading would break the layout

10.2 When Bootstrap 4 Is Still Relevant

Projects that already use Flexbox
Designs that depend on Bootstrap 4’s components
Sites not yet ready to drop jQuery

10.3 Should You Upgrade to Bootstrap 5?

In most cases, yes. Upgrading may require refactoring but provides long-term benefits.

11. The Future of Bootstrap

Bootstrap continues to evolve. Future releases may include:

More custom properties
Better accessibility
Improved JavaScript plugins
More utility-first features
Faster performance

The Bootstrap team has also shown interest in integrating CSS Grid more deeply.