<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css"> <script src="//maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js"></script> <script src="//code.jquery.com/jquery-1.11.1.min.js"></script> <!------ Include the above in your HEAD tag ----------> <div id="ThumbnailCarousel" class="carousel slide col-xs-12" data-ride="carousel"> <div class="carousel-inner"> <div class="carousel-item active"> <div class="row"> <div class="col-md-3 col-sm-6"><a href="#x" class="thumbnail"><img src="http://placehold.it/250x250" alt="Image" class="img-fluid img-thumbnail"></a> </div> <div class="col-md-3 col-sm-6"><a href="#x" class="thumbnail"><img src="http://placehold.it/500x500" alt="Image" class="img-fluid img-thumbnail"></a> </div> <div class="col-md-3"><a href="#x" class="thumbnail"><img src="http://placehold.it/250x250" alt="Image" class="img-fluid img-thumbnail"></a> </div> <div class="col-md-3"><a href="#x" class="thumbnail"><img src="http://placehold.it/250x250" alt="Image" class="img-fluid img-thumbnail"></a> </div> </div> </div> <div class="carousel-item"> <div class="row"> <div class="col-sm-3"><a href="#x" class="thumbnail"><img src="http://placehold.it/250x250" alt="Image" class="img-fluid img-thumbnail"></a> </div> <div class="col-sm-3"><a href="#x" class="thumbnail"><img src="http://placehold.it/500x500" alt="Image" class="img-fluid img-thumbnail"></a> </div> <div class="col-sm-3"><a href="#x" class="thumbnail"><img src="http://placehold.it/250x250" alt="Image" class="img-fluid img-thumbnail"></a> </div> <div class="col-sm-3"><a href="#x" class="thumbnail"><img src="http://placehold.it/250x250" alt="Image" class="img-fluid img-thumbnail"></a> </div> </div> </div> <div class="carousel-item"> <div class="row"> <div class="col-sm-3"><a href="#x" class="thumbnail"><img src="http://placehold.it/250x250" alt="Image" class="img-fluid img-thumbnail"></a> </div> <div class="col-sm-3"><a href="#x" class="thumbnail"><img src="http://placehold.it/500x500" alt="Image" class="img-fluid img-thumbnail"></a> </div> <div class="col-sm-3"><a href="#x" class="thumbnail"><img src="http://placehold.it/250x250" alt="Image" class="img-fluid img-thumbnail"></a> </div> <div class="col-sm-3"><a href="#x" class="thumbnail"><img src="http://placehold.it/250x250" alt="Image" class="img-fluid img-thumbnail"></a> </div> </div> </div> </div> <a class="carousel-control-prev" href="#ThumbnailCarousel" role="button" data-slide="prev"> <span class="carousel-control-prev-icon" aria-hidden="true"></span> <span class="sr-only">Previous</span> </a> <a class="carousel-control-next" href="#ThumbnailCarousel" role="button" data-slide="next"> <span class="carousel-control-next-icon" aria-hidden="true"></span> <span class="sr-only">Next</span> </a> </div>

#ThumbnailCarousel img { } #ThumbnailCarousel div { height:250px; width:100%; } #ThumbnailCarousel.carousel { padding-top:30px; text-align:center; } .col-md-3 .img-thumbnail { height:100%; }