We are proud to share it with you and hear your feedback as well .Bootstrap 4 has been a massive undertaking that touches over all line of the code.
There are a lots of major changes to Bootstrap and we mention some of our favorites:
- Moved from Less to Sass. By Libsass, Bootstrap now compiles faster than ever and we joined an increasingly large community of Sass developers.
- Improved grid system. We’ve added a new grid tier to better target mobile devices and completely overhauled our semantic mixings.
- Dropped wells, thumbnails, and panels for cards. Cards are a brand new component to Bootstrap, but they’ll feel super familiar as they do nearly everything wells, thumbnails, and panels did, only better.
Consolidated all our HTML resets into a new module, Reboot. Reboot steps in where Normalize.css stops, giving you more opinionated resets like
box-sizing: border-box, margin tweaks, and more all in a single Sass file.
- Brand new customization options. Instead of relegating style embellishments like gradients, transitions, shadows, and more to a separate stylesheet like v3, we’ve moved all those options into Sass variables. Want default transitions on everything or to disable rounded corners? Simply update a variable and recompile.
- Dropped IE8 support and moved to rem and em units. Dropping support for IE8 means we can take advantage of the best parts of CSS without being held back with CSS hacks or fallbacks. Pixels have been swapped for rems and ems where appropriate to make responsive typography and component sizing even easier. If you need IE8 support, keep using Bootstrap 3.
- Improved auto-placement of tooltips and popovers.
- Improved documentation.
And that barely scratches the surface of the 1,100 commits and 120,000 lines of changes in v4 so far. Plus, we’re not even done yet! but coming soon