The Bootstrap Blog

News and announcements for all things Bootstrap, including new releases and Bootstrap Themes.

Bootstrap 4 Beta 2

Just over two months ago we shipped our first beta for Bootstrap 4, and now we’re ready to share our second with you. We’ve improved customization, documentation, build tooling, and naming inconsistencies all while fixing hella bugs.

We’ve done our best to prevent breaking changes, but we had to sneak some in. Regrettably, we’ll also have a few more coming in Beta 3, too. However, we’re clearly outlining all of them for you to make the upgrade and testing process as easy as possible.

Let’s start with the good news though—Beta 2 is here!


We’ve pushed over 500 commits in our two months, so we have a few changes since Beta 1 to highlights to share with you.

Improved theming

Bootstrap Theming docs page

We have a brand new Theming docs page to replace our old Options page (we’ll automatically redirect folks from the old page). This new page delves into the structure of our Sass files, default variables and customizing them, maps and loops we use, functions, colors, and of course or global Sass options. It also includes a new section to explain how we build our components via Sass maps and loops, specifically our modifier classes (e.g., .btn-danger).

In addition to the documentation changes, we’ve made a few CSS changes to improve how folks interact with our theming options.

Lastly, our $enable-shadows and $enable-gradients Sass variables have finally been updated and integrated into several of our components. Now, when you enable those variables (both are false by default) and recompile, you’ll see subtle gradients and shadows across alerts, buttons, carousels, custom form controls, and dropdown items.

Themed buttons

And when you use $enable-gradients, you’ll enable the new .bg-gradient- utilities (disabled by default) for use in navbars and more.

Themed backgrounds

Check it out and please share any feedback in an issue.

Offset grid classes

We brought them back! Prematurely removed ahead of Beta 1, we underestimated the appeal of the .offset- classes for our grid system. Auto margins are simply not enough for y’all. The styles have been restored and our grid docs have been updated. Enjoy!

Updated migration docs

Given our handful of breaking changes since Beta 1, we added a new section to our migration docs page to detail exactly what we changed that might be broken for you. We had to rename a few classes here and there to ensure everything’s consistent with the rest of the project.

We’ll be updating this page again for Beta 3 in the same way.

And more!

Coming in Beta 3

Beta 3 is up next for us and already has a GitHub project board setup to track issues and PRs. Beyond the standard docs improvements and bug fixes, there are a few issues and PRs that are of mind for us:

Be sure to follow those issues and PRs if you’re interested in when the merge to our v4-dev branch.

Getting to v4 Final

After Beta 3, we’re hoping to quickly move into a final v4 release. Ideally, it’ll also be a smoother and more focused release than the Alpha 6 to Beta 1 move. We heard from a lot of you that the delta between those two releases was too great.

For more details on this release’s changes, take a look at the Beta 2 ship list issue, as well as the Beta 2 project. Be sure to join our official Slack room! and dive into our issue tracker with bug reports, questions, and general feedback whenever possible.

@mdo & team