Alpha 6 has landed, and it’s one of our biggest ships to date. We’ve rewritten our grid system and all major components in flexbox, forging ahead with it as our default layout option as we drop IE9 support. With 700 commits since our last release, we have some catching up to do.
Read one for highlights from this release. We also recommend reviewing the ship list and milestone for a more detailed look at what’s changed.
Embracing Flexbox
Bootstrap 4 is now flexbox by default! Flexbox is an immensely powerful layout tool, providing unparalleled flexibility (hah) and control to our grid system and core components. It comes at the cost of dropping IE9 support, but brings significant improvements to component layout, alignment, and sizing.
If you’re unfamiliar with flexbox, here’s some of the power you can expect to utilize in Bootstrap 4:
Automatic equal-width grid columns (e.g., two columns are automatically 50% wide)
Equal height and equal width cards
Vertical and horizontal centering without hardcoding values with translate or margin
Utility classes for easily (and responsively!) changing display, direction, alignment, and more
Auto margins for easy spacing
Justified navigation and button groups
No more HTML white space or broken table-style rendering
Nearly every component now takes advantage of flexbox in place of display: table hacks and floats. That means less reliance on clearfix, more control over DOM and visual order, and fewer bugs. Navs, list groups, cards, and more all utilize flexbox. Even more complex components like the carousel have been modified to use flexbox in some places.
With Alpha 6, we’ve made Bootstrap’s extensive suite of utilities—including classes for display, float, and flexbox, and more—completely responsive. To keep these class names as approachable and representative of their scope as possible, we’ve also made two important changes to their naming scheme.
First, we’ve dropped the -xs infix from our lowest (extra small) breakpoint. xs isn’t a responsive breakpoint quite like sm, md, lg, and xl because it doesn’t start applying styles at a min-width and up. It simply applies to everything as there’s no bounding @media query.
Second, we’ve renamed several classes to better articulate their property-value pairings. Instead of pull, we use float. Instead of creating new names for the various flexbox properties, we start with the property name.
Put that all together and you end up with updated classes like .col-6, .d-none, .float-right, .d-md-flex, .justify-content-end, and .text-lg-left. These new classes bring immense power and customization to folks building with Bootstrap. They also make it easier for those migrating from v3 with clearer mappings to legacy class names.
More grid improvements
We’re back at it with more grid improvements. This time we’ve added responsive autosizing columns and more container padding options. Add any number of .col-* classes and they’ll automatically be equal in width.
Padding for grid containers can now be configured across breakpoints with the new $grid-gutter-widths Sass map. In addition, you can remove gutters from grid rows and their columns with the .no-gutters modifier.
Updated navbar
As mentioned in our last release, the Alpha 5 navbar was a little half baked. This time around, we’re completely baked. No, but seriously, the navbar has been rewritten to provide better built-in responsive behaviors and improved layout customization thanks to our move to flexbox.
Here’s the rundown on what’s changed:
Navbars are built with flexbox! Instead of floats, you’ll need flexbox and margin utilities.
Navbar navs no longer require the .nav base class. While it provided a starting point, these shared styles often got in the way of navbar behaviors. Now it’s just .navbar-nav and utilities for alignment.
The .navbar-toggleable classes are now applied to the .navbar instead of the .collapse within. This allows us to provide better responsive behavior with just one class change.
The responsive navbar toggle, .navbar-toggler, has also been updated. The icon is once again a child element, .navbar-toggler-icon, for improved customization. It also includes easy modifiers for absolutely aligning it to the top right or top left.
Check out the navbar docs to learn more and see it in action.
Up next, our first beta
Like you, we’re very much ready for our first beta release. Luckily, we’re in great shape to get there from this alpha. We have the fewest open issues and pulls we’ve had in easily the last 18 months, and the contributions from the community have been outstanding. As we head to our first beta, we’ll be focused on not adding anything new, ideally making as few breaking changes as possible, and emphasizing documentation quality and bug fixes.
We need your help to get there though. Please dive into this latest release and continue to report bugs and submit pull requests as you can. Every bit helps us improve the next release!
Alpha 5 has arrived just over a month after Alpha 4 with some major feature improvements and a boat load of bug fixes. We still have a lot of work to do, but we’re closing the gap and getting more stable with each release. Keep reading for the highlights and plans for Alpha 6.
New CSS bundles
We’ve updated our build process to include compiled versions of all our CSS bundles. In addition to the longstanding default compiled and minified bundles, we now include compiled CSS files for our flexbox mode, grid system only, and Reboot only bundles. Each bundle includes a compiled, minified, and Sass map, just like the default compiled CSS.
Grid updates
Our grid system has been updated and is more flexible than ever. New in Alpha 5 are breakpoint specific grid gutters. That’s right, now you can customize the width of your gutters across each and every grid tier by modifying the Sass map.
The .container behaviors have changed slightly in Alpha 5. We now set the width of each container alongside a max-width: 100%; to ensure proper rendering across browsers in both our default and flexbox modes. Similarly, we fixed a bug in our flexbox grid where columns didn’t properly collapse at lower breakpoints.
Lastly, we’ve changed a few breakpoint and container dimensions. The sm tier’s container is now smaller than it’s viewport dimensions and the lg tier has changed from 940px to 960px for grid columns that more cleanly by 12.
Utilities overhaul
Utility classes got a ton of attention with Alpha 5 and will continue to in Alpha 6. Major changes in this release include:
Simpler margin and padding syntax (e.g., now mx-auto instead of m-x-auto).
Renamed .pull-*-left and .pull-*-right to their CSS properties (e.g., now .float-*-left and .float-*-right).
Separated background and color utilities for more explicit styling.
Renamed image utilities, moving from .img-rounded and .img-circle to .rounded and .rounded-circle, respectively.
Removed the display: block; from .img-fluid as it’s unnecessary for creating responsive images (the inline-block default works great as-is).
Added new vertical-align utilities with .align-top, .align-middle, and more.
Be sure to scope out the open issues in the Alpha 6 milestone. There are more updates coming to utilities to add more responsive variations, more consistent naming, and more.
Navbar updates
We’ve put a ton of time into the navbar for Alpha 5, but honestly it’s still not done. Rather than hold back the progress we’ve made for it until Alpha 6, we’re including a somewhat half-baked iteration.
Here’s a look at what’s new, how it works, and what might change in our next release.
First up, the navbar has a brand new toggler that features a customizable SVG-based background-image. With the power of Sass variables, that allows us to easily change the color of those hamburger menu icons.
Second, the default styles for the brand and navigation have largely been tweaked. There’s less custom styling overall and an emphasis on positioning and flexibility.
Building on that, we overhauled the collapse plugin integration for responsive navbars. With the help of some utility classes and collapse classes for each grid tier, you can easily pick the breakpoint for collapsing your navbar without having to recompile your Sass. Also included is the auto restyling of dropdown menus for mobile so they no longer hide other navbar content when toggled.
Lastly, we’ve updated the styling and documentation for various navbar subcomponents. There’s more flexibility and examples of the .navbar-brand, better form control support, higher nav contrast, themed responsive toggles, and more.
The navbar is a tricky one—there’s so much functionality and styling that can go into them. We’ve outlined the next major pieces for the navbar, but there’s likely more we’re missing. Be sure to give the updated component a whirl and report back with your feedback.
Getting to Alpha 6
We’re planning on one more major alpha release before getting into the slightly more stable beta ships. There’s still more to do around our major components—the navbar, flexbox variants, utilities, and accessibility—before we button things up.
Once done, we’ll review all on our docs and update all our example templates to the latest and greatest. From there we’ll need your help to test these changes and report bugs. Stay tuned for more updates as we get closer to that release.
Alpha 4 is here to address those pesky build and package errors, a few CSS bugs, and some documentation inconsistencies we introduced in our last release.
This is a super small release compared to our previous alphas, so here’s the rundown on what’s changed:
Fixed package.json errors
Additional migration notices for more components
Fix broken flexbox utilities on flexbox grid page
Fix inconsistent checkbox and radio markup, as well as validation styles
Minor tweaks to cards, alerts, utilities, and input groups
At the time of release, the Bootstrap CDN hasn’t been updated for Alpha 4. Apologies for the delay, and stay tuned for an update on when they’re live.
Alpha 3 has landed! We have an overhauled grid, updated form controls, a new font stack, tons of bug fixes, and more. It’s been several months since our last update, but the size of this update should help get us back on track.
Work on Alpha 3 started rather broadly, addressing bug fixes and docs updates of all shapes and sizes, but finished with a narrow focus on our form controls and grid system. If you’ve followed the development in our v4-dev branch, you might already be familiar with some of these bigger changes.
The grid system was overhauled with three major pull requests—#19099, #20349, and #20361. Those PRs largely focused on the following changes:
Our ready-made grid classes (containers and columns) are now behind a Sass variable, meaning grid classes can easily be disabled via Sass variable. Update the boolean $enable-grid-classes variable and recompile to remove them.
Grid modifier classes are simpler and no longer require the col- prefix. For example, instead of .col-offset-*-*, .col-push-*-*, and .col-pull-*-*, we now have .offset-*-*, .push-*-*, and .pull-*-*.
Mixins have been changed, and then changed again, to in an effort to keep generated classes simple and cooperative between standard and flexbox modes. Our two primary column mixins are now make-col-ready, which houses the position, padding-*s, and min-height (to prevent collapsing empty columns), and make-col for setting the float and width.
Added a grid customization section to the docs to explain how to change the number of columns, grid tier breakpoints, container widths, and more.
These changes are available in our standard grid, as well as our flexbox grid. More on that below.
Flexbox
Flexbox mode has been updated across the board in Alpha 3, starting from the grid system (it uses the same variable and the updated Sass mixins) and moving through our utilities and components.
New flexbox grid docs. In addition to the standard grid docs, we now have a dedicated docs page for our flexbox grid as it behaves slightly differently than the standard grid. This new page includes details on how and why this grid works the way it does, as well as additional code examples.
Automatic equal-width column sizing with new .col-{breakpoint} classes. For example, for three equal-width columns at the xs breakpoint, you’d create three columns each with just .col-xs.
New flexbox alignment utility classes for vertically and horizontally distributing items. Works with our flexbox grid, as well as just about any other custom component.
Forms
Forms saw a ton of activity early on in Alpha 3’s development. Documentation, class names, layout options, and validation styles have all been drastically improved.
New classes for checkboxes, radios, input sizing, and legends. While not 100% final, all our form controls are named more clearly and consistently across our CSS.
Replaced the base64 PNG background images with inline SVGs for our custom form controls and validation states. Scale those form controls to your heart’s content!
Speaking of validation states, we have brand new form validation and help text options. Validation states can now be applied on a per-input basis (with .form-control-{state}) and optional validation feedback can be shown with .form-control-feedback. Independent form help text can now be controlled with the new .form-text class.
<divclass="form-group has-success"><labelclass="col-form-label"for="inputSuccess1">
Input with success
</label><inputtype="text"class="form-control form-control-success"id="inputSuccess1"><divclass="form-control-feedback">
Success! You've done it.
</div><smallclass="form-text text-muted">
Example help text that remains unchanged.
</small></div>
Fixed a few form related bugs, like the horizontal label padding in #17498, misuse of <fieldset>s for form groups, sizing classes not applying to <select>s, and more.
Documentation for forms has been overhauled. We have simpler examples of our available form controls, clearer guidance on validation states (and when to use each), and more.
System fonts
We’ve replaced the decades old Helvetica/Arial font stack with a system font stack, utilizing newer, more readable, and more powerful fonts that companies like Apple, Google, and Microsoft have specifically designed for today’s devices.
Originally this was planned to affect Linux users, but font usage and support is rather inconsistent across distros and user preferences. For that reason, there’s no intended font change for folks on Linux.
And so much more…
There were nearly 1,200 commits to Alpha 3 and this post barely scratches the surface. We’ve fixed dozens of other bugs and worked hard to improve our documentation across the board.
More exploration, more bugfixes, more docs updates, and, best of all, more alphas. The daily grind keeps us super busy these days, but we’ll do our best to keep the momentum going. Stay tuned!