<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css"> <script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script> <script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script> <!------ Include the above in your HEAD tag ----------> <div class="collapse navbar-collapse" id="navbarSupportedContent"> <ul class="navbar-nav ml-auto"> <li class="nav-item dropdown"> <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false"> Click Me! </a> <!-- Here's the magic. Add the .animate and .slide-in classes to your .dropdown-menu and you're all set! --> <div class="dropdown-menu dropdown-menu-right animate slideIn" aria-labelledby="navbarDropdown"> <a class="dropdown-item" href="#">Action</a> <a class="dropdown-item" href="#">Another action</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="#">Something else here</a> </div> </li> </ul> </div>

@keyframes slideIn { 0% { transform: translateY(1rem); opacity: 0; } 100% { transform:translateY(0rem); opacity: 1; } 0% { transform: translateY(1rem); opacity: 0; } } @-webkit-keyframes slideIn { 0% { -webkit-transform: transform; -webkit-opacity: 0; } 100% { -webkit-transform: translateY(0); -webkit-opacity: 1; } 0% { -webkit-transform: translateY(1rem); -webkit-opacity: 0; } } .slideIn { -webkit-animation-name: slideIn; animation-name: slideIn; }