NEW EDIT 20/8/2015 Now, after you edit your css file, you just need to edit CAROUSEL.TRANSITION_DURATION (in bootstrap.js) or c.TRANSITION_DURATION (if you use bootstrap.min.js) and to change the value inside it (600 for default). The final value must be the same that you put in your css file( for example 10s in css = 10000 in .js)