Bootstrap class: **.align-self-*-start**

<div class="align-self-start">Aligned flex item</div>

<!-- responsive variations -->
<div class="align-self-sm-start">Aligned flex item</div>
<div class="align-self-md-start">Aligned flex item</div>
<div class="align-self-lg-start">Aligned flex item</div>
<div class="align-self-xl-start">Aligned flex item</div>

Preview

Flex item 1

Aligned flex item

Flex item 3

Tips 💡

You don't need to remember all CSS classes. Just use the Bootstrap Editor instead.

More in Bootstrap Flexbox

Bootstrap 4 & 5