<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"> <!-- Button trigger modal --> <button type="button" class="btn btn-primary btn-lg" data-toggle="modal" data-target="#myModal"> Launch demo modal </button> <!-- Modal --> <div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true"> <div class="modal-dialog"> <div class="modal-content"> <div class="modal-header"> <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">×</span></button> <h4 class="modal-title" id="myModalLabel">Modal title</h4> </div> <div class="modal-body"> ... </div> <div class="modal-footer"> <button type="button" class="btn btn-default" data-dismiss="modal">Close</button> <button type="button" class="btn btn-primary">Save changes</button> </div> </div> </div> </div> </div> </div>

function centerModal() { $(this).css('display', 'block'); var $dialog = $(this).find(".modal-dialog"); var offset = ($(window).height() - $dialog.height()) / 2; // Center modal vertically in window $dialog.css("margin-top", offset); } $('.modal').on('show.bs.modal', centerModal); $(window).on("resize", function () { $('.modal:visible').each(centerModal); });