<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 ----------> <nav class="navbar navbar-expand-lg navbar-dark fixed-top bg-dark"> <a class="navbar-brand" href="">Brand</a> <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarCollapse" aria-controls="navbarCollapse" aria-expanded="false" aria-label="Toggle navigation"> <span class="navbar-toggler-icon"></span> </button> <div class="collapse navbar-collapse bg-dark" id="navbarCollapse"> <ul class="navbar-nav mr-auto"> <li class="nav-item active"> <a class="nav-link" href="#">Home</a> </li> <li class="nav-item"> <a class="nav-link" href="#">Link</a> </li> <li class="nav-item"> <a class="nav-link" href="#">About</a> </li> </ul> <form class="form-inline mt-2 mt-md-0"> <input class="form-control mr-sm-2" type="text" placeholder="Search"> <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button> </form> </div> </nav>

@media (max-width: 992px) { .navbar-collapse { position: fixed; top: 50px; left: 0; padding-left: 15px; padding-right: 15px; padding-bottom: 15px; width: 75%; height: 100%; } .navbar-collapse.collapsing { left: -75%; transition: height 0s ease; } .navbar-collapse.show { left: 0; transition: left 300ms ease-in-out; } .navbar-toggler.collapsed ~ .navbar-collapse { transition: left 500ms ease-in-out; } }