<link href="//netdna.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css"> <script src="//netdna.bootstrapcdn.com/bootstrap/3.2.0/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-xs-6 text-center"> <h3 class="lead">Normal image</h3> <img src="http://lorempixel.com/400/400/people/4/" /> </div> <div class="col-xs-6 text-center"> <h3 class="lead">Muted image</h3> <img src="http://lorempixel.com/400/400/people/4/" class="img-muted" /> </div> </div> <p class="text-center text-muted" style="margin-top: 40px"><em>Thanks to <a href="http://demosthenes.info/blog/532/convert-images-to-black-and-white-with-css">demosthenes.info</a> for filter trick</em></p> </div>

.img-muted { -webkit-filter: grayscale(100%); -moz-filter: grayscale(100%); filter: grayscale(100%); filter: url("data:image/svg+xml;utf8,<svg version='1.1' xmlns='http://www.w3.org/2000/svg' height='0'><filter id='greyscale'><feColorMatrix type='matrix' values='0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0 0 0 1 0' /></filter></svg>#greyscale"); }