<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 ----------> <button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModalLong"> ici, modal fullscreen avec iframe </button> <!-- Modal --> <div class="modal fade" id="exampleModalLong" tabindex="-1" role="dialog" aria-labelledby="exampleModalLongTitle" aria-hidden="true"> <div class="modal-dialog" role="document"> <div class="modal-content"> <div class="modal-header"> <h5 class="modal-title" id="exampleModalLongTitle">Modal title</h5> <button type="button" class="close" data-dismiss="modal" aria-label="Close"> <span aria-hidden="true">×</span> </button> </div> <div class="modal-body"> <iframe src="https://www.lipsum.com/" width="100%" frameBorder="0"></iframe> </div> <div class="modal-footer"> <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button> <button type="button" class="btn btn-primary">Save changes</button> </div> </div> </div> </div>

.modal-body { max-height: 75vh; padding:0; } .modal-dialog { max-width: 100%; margin: 0.1rem auto; } .modal iframe { height:75vh; }