Bootstrap 4: What’s New

A Visual Guide to The Next Bootstrap

Carol Skelly
Published in
7 min readJun 6, 2016


Recently, there has been a lot of talk about what’s new in Bootstrap 4, and I was curious to examine the visual appearance & style differences. Here is a visual guide that will show you what’s new in Bootstrap 4 as compared to Bootstrap 3.

Heads up Aug 2017__ Bootstrap 4 Beta is out! See my latest on what’s new and changed for the long-awaited BS4 beta release.

Panels are now Cards

What you notice first in Bootstrap 4 is that .panel and .well have been replaced by .card. This makes a lot of sense as cards are one of the more well known trends in responsive design. The Bootstrap 4 Cards can be singular, grouped together or equal height. In their default form, you’ll see they look almost the same.

Bootstrap 3 Panel vs. Bootstrap 4 Card

But thanks to flexbox it’s now much easier to create groups of same height cards

The contextual card colors are still there in Bootstrap 4, but they’re now bolder with inverse backgrounds.

Bootstrap 4 Context Background Colors

Additionally, there are outline cards for when you want the contextual color without the bold background color.

Fonts are Bigger

As you may have noticed with the cards, it’s very apparent that typography is larger in Bootstrap 4. The default font size went from 14px to 16px in the new Bootstrap 4. There are also new large display headings to make text that really stands out. All of the font sizing in Bootstrap 4 is completely based on `rem` units so that all font sizes are relative to the root element.

Typeface is larger in Bootstrap 4

The Grid Has Changed

Looking back at Bootstrap 3, the 4 grid tiers (‘xs’, ’sm’, ‘md’ and ‘lg’ breakpoints) worked looked like this..

Bootstrap 3 large tier
Bootstrap 3 medium tier
Bootstrap 3 small tier
Bootstrap 3 extra small tier

As you can see in Bootstrap 3, the smallest breakpoint has a wide range of devices less than 768px in width. As a result, there’s no simple way to create different grid layouts for typical smartphone screens (~375px). There is also no way to distinguish between portrait and landscape mode on mobile devices.

The Bootstrap 4 Grid

Introducing the new XL grid tier

Looking ahead to Bootstrap 4, the new grid tier provides better support for typical smaller device widths. Now there are 5 tiers (or breakpoints) to support typical portrait and landscape screen widths.

Bootstrap 4 introduces a new grid breakpoint with the col-xl-* classes. This extra tier extends the media query range all the way down to 544 px (or 34 em based on the new sizing). Eventhough the new XL tier would make one think it’s been added to support extra large screens, it’s actually the opposite.

All the 3.x tiers slide up in 4.x, to fit in the new 544 px to 768 px tier at the bottom. While the old 3.x col-xs-* supported screen widths under 768 px, the new 4.x col-xs-* tier supports screen width under 544 px. This new smaller xs tier means improved support portrait smartphones.

Desktop and laptops

The XL breakpoint is screen widths > 1200px

Landscape tablets

The LG breakpoint is screen widths > 992px

Portrait tablets & landscape phablets

The MD breakpoint is screen widths > 768px

Phablets & landscape smartphones

The SM breakpoint is screen widths > 544px

Portrait smartphones

The XS breakpoint is screen widths < 544px

In BS 4, the additional tier allows us to target smaller devices less than 544 px, and create layouts specifically for this screen width. Try this example snippet to see how all of the BS 4 grid breakpoints work.

Bootstrap 4 Grid Demo

Many Little Things

An obvious difference between 2.x to 3.x was the move from gradient to flat design which was most apparent in nav and button styling. Bootstrap 4 is more subtle in it’s look-and-feel. Take for example the buttons. They’re still flat, and now come in new outline flavor.

Bootstrap 4 Buttons

Utility Classes

One of my favorite new features in Bootstrap 4 is the addition of responsive floats that enable you to float an element (left, right) based on the grid tier. Lack of this feature was often an obstacle that required custom CSS media queries, and classes in Bootstrap 3. Consider a scenario where we only want to right-align elements (float:right) on specific breakpoints, and otherwise return to the default behavior of float:none. Here float-md-right is used to float right only on the medium grid tier.

Similarly, the text alignment classes can be used for responsive text positioning in Bootstrap 4.

Additionally, there are some handy spacing utility classes that enable better control of horizontal & vertical space using variable margins and padding around elements. At first, you might think these spacing classes are useless bloat. However, do you remember attempting any of the following with Bootstrap 3?

  • Shrinking the gutter/padding between columns
  • Add vertical white-space after rows & columns
  • Reduce horizontal white-space between elements
  • Stack 2 headings without huge margins under the first

In Bootstrap 4, the spacing utils make it easy to change horizontal or vertical whitespace. There is also a new .no-gutters class to remove the gutter (spacing between columns) from the gridrow.

As of this writing, Bootstrap 4 is still in alpha, and the best way to track progress is over at the official Bootstrap blog.

Update July 2016

Bootstrap 4 Alpha 3 Released

The latest alpha 3 release is out, and there are a few new changes to look at. Here’s a summary…

Tags: The new tag component replaces the old label.

Fonts: The new native font stack is now the default.

Update Sept 2016

Bootstrap 4 Alpha 4

Now that Bootstrap 4 alpha 4 is out, the makers of Bootstrap have announced that they are halting development on Bootstrap 3, to make faster progress on Bootstrap 4.

Update Jan 2017

Bootstrap 4 Alpha 6

With this latest release, Bootstrap is now flexbox by default, so there is no longer a $enable_flexbox variable. There has also been some renaming to simplify and intuitize class names. The most significant being the drop of the -xs column suffix, so for example you’d use col-6 instead for col-xs-6. The other breakpoints: sm, md, lg, and xl remain the same.

Flexbox is also now used for the Navbar component (instead of floats), and there have been a few changes to the Navbar classes to make varying breakpoints and content alignment easier. There are also many flexbox utility classes that make various flexbox-based layouts super simple. The Alpha 6 release also means that the Bootstrap 4 Beta will be up next!

Update May 2018

Bootstrap 4 was officially released several months ago, and is currently at version 4.1.1. For the latest on Bootstrap 4.1, check out these new articles…



Carol Skelly

S/W Engineer. Web developer. @Bootply @Codeply