I'm making a slide out menu with HTML and CSS3 - especially transitions. I would like to know what is best practice / best performance to slide a relatively positioned div horizontally. When i click a button it adds a class to my div. Which class is better? (Note I can add all the browser prefixes later and this site only targets modern browsers). //option 1 .animate{ -webkit-transition:all ease 0.3s; -webkit-transform:translateZ(200px); } //option 2 .animate{ -webkit-transition:all ease 0.3s; left:200px; } Thanks