<div class="row">
<div class="col-md-4 d-flex align-items-stretch">
<div class="card">
<!-- Your content here -->
</div>
</div>
<div class="col-md-4 d-flex align-items-stretch">
<div class="card">
<!-- Your content here -->
</div>
</div>
<div class="col-md-4 d-flex align-items-stretch">
<div class="card">
<!-- Your content here -->
</div>
</div>
</div>
Adding d-flex align-items-stretch to the column classes will make each column stretch to the same height. Just wrap your content in a .card or similar container. This will make all columns in the row equal in height, regardless of their content.
Give that a shot and see how it works!
This I used in my project