Bootstrap

Bootstrap is a popular CSS framework that provides pre-built components, a responsive grid system, and utility classes for rapidly building consistent web interfaces. Originally developed at Twitter, it offers a comprehensive set of styled elements including navigation bars, modals, forms, cards, buttons, and dropdown menus that work across browsers with minimal custom CSS.

The framework uses a 12-column grid layout with responsive breakpoints, allowing developers to create layouts that adapt from mobile to desktop screens using declarative CSS classes. Bootstrap 5 dropped the jQuery dependency, uses vanilla JavaScript for interactive components, and introduced an expanded utility API that moves closer to the utility-first approach popularized by Tailwind CSS.

For web development, Bootstrap dramatically reduces the time needed to build a functional, responsive interface. It is particularly valuable for admin panels, internal tools, prototypes, and projects where custom visual design is not a priority. The tradeoff is that Bootstrap sites tend to look similar without significant customization, and the framework ships more CSS than most projects need. Despite newer alternatives, Bootstrap remains one of the most widely used CSS frameworks due to its extensive documentation and large community.