<title>Bootstrap 4 Images Center Aligned</title>
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@4.6.0/dist/css/bootstrap.min.css" crossorigin="anonymous">
<script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.1/dist/umd/popper.min.js" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/bootstrap@4.6.0/dist/js/bootstrap.min.js" crossorigin="anonymous"></script>
<h2>Bootstrap 4 Images Center Aligned</h2>
<p>Add <code>.mx-auto</code> and <code>.d-block</code> class to center align images.</p>
<img src="bridge-demo.jpg" class="mx-auto d-block" alt="Image">