<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css"> <script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/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 class="container"> <div class="row"> <div class="col-md-6"> <div class="panel panel-default"> <div class="panel-heading"> <a href="#panel-1" data-toggle="collapse"> Panel 1 </a> </div> <div class="panel-body collapse" id="panel-1"> Panel content </div> </div> </div> <div class="col-md-6"> <div class="panel panel-default"> <div class="panel-heading"> <a href="#panel-2" data-toggle="collapse"> Panel 2 </a> </div> <div class="panel-body collapse" id="panel-2"> Panel content </div> </div> </div> </div> </div>

.panel>.panel-heading a:only-child[data-toggle="collapse"] { width: 100%; display: block; }