Pick a version below. Each major version of Bootstrap changed enough — grid system, dependencies, components — that it's worth learning as its own track.
Each track has its own step-by-step lessons, real code examples, and a dedicated sidebar so you always know what's next.
The classic version — col-xs/col-sm/col-md grid, Glyphicons, and jQuery-powered components. This is the version this very site is built with.
A Sass-based rewrite with a flexbox grid, the new Card component, and utility classes — still requires jQuery and Popper.js.
Start LearningThe current version — drops the jQuery dependency entirely, refreshes utilities and forms, and adds components like Offcanvas.
Start Learning