Mobile first approach. Starting with version 2.0 the framework supports responsive web design, where the layout of web page adjusts dynamically according to the type and size of device it is viewed on. Since version 3.0, Bootstrap implements a mobile first design styles throughout the entire library.

Responsive Grid. Bootstrap features a responsive 12 column grid system. These grids have classes xs, sm, md and lg each defined in sync with the device resolution. All the developer needs to do is to apply these classes while defining the visibility of an element in the markup. Development of the responsive websites has never been so easy.

Rich feature set. Bootstrap provides dozens of custom HTML and CSS components, JavaScript plugins, responsive 12-column grids, typography, form controls, and a web-based Customizer. Either a fixed or a responsive grid, offsetting and nesting of columns