twitter-bootstrap Migrating to Bootstrap 4 Bootstrap 4 Vertical Align
Example
Getting elements to center or bottom align vertically has always been a challenge with CSS and Bootstrap. The desired vertical alignment may be within a parent container, or relative to adjacent elements.
Now that Bootstrap 4 is flexbox by default there are many different approaches to vertical alignment using: Auto-margins, Flexbox Utilities, or the Display Utilities along with Vertical Align Utilities.
At first, the Vertical Alignment Utilities would seem an obvious choice, but these only work with inline and table display elements. Here are some Bootstrap 4 vertical alignment options and scenarios...
1 - Vertical Center Using Auto Margins:
One way to vertically center is to use my-auto. This will center the element within it's container. For example, h-100 makes the row full height, and my-auto will vertically center the col-sm-12 column.
<div class="row h-100">
<div class="col-sm-12 my-auto">
<div class="card card-block w-25">Card</div>
</div>
</div>
Vertical Center Using Auto Margins Demo
my-auto represents margins on the vertical y-axis and is equivalent to:
margin-top: auto;
margin-bottom: auto;
2 - Vertical Center with Flexbox:
Since Bootstrap 4 .row is now display:flex you can simply use align-self-center on any column to vertically center it...
<div class="row">
<div class="col-6 align-self-center">
<div class="card card-block">
Center
</div>
</div>
<div class="col-6">
<div class="card card-inverse card-danger">
Taller
</div>
</div>
</div>
or, use align-items-center on the entire .row to vertically center align all col-* in the row...
<div class="row align-items-center">
<div class="col-6">
<div class="card card-block">
Center
</div>
</div>
<div class="col-6">
<div class="card card-inverse card-danger">
Taller
</div>
</div>
</div>
Vertical Center Different Height Columns Demo
3 - Vertical Center Using Display Utils:
Bootstrap 4 has display utils that can be used for display:table, display:table-cell, display:inline, etc.. These can be used with the vertical alignment utils to align inline, inline-block or table cell elements.
<div class="row h-50">
<div class="col-sm-12 h-100 d-table">
<div class="card card-block d-table-cell align-middle">
I am centered vertically
</div>
</div>
</div>
Vertical Center Using Display Utils Demo
