The default value is 1.0, meaning the window transition begins once the overlay transition has finished. 2) It seems, bootstrap v3 modal HTML template requires, “” and which needs to around model-header and model-body divs. 33 Bootstrap 4 Carousel Examples To Give A Better End User Experience. Best way I found for all HTML5 browsers: body.modal-open .modal { Bootstrap modal center horizontally How Can I Put Bootstrap Modal in Horizontally center?, your current code in jsfiddle would help out a lot but can you try: .modal { width: 600px; //size of modal margin: 0 auto; }. left: 50%; 33 Bootstrap 4 Carousel Examples To Give A Better End User Experience. A stunning collection of responsive galleries created with the latest Bootstrap 5. Last Modified: Feb. 19, 2021, 3:41 p.m. Bootstrap recently released version 5.0.0 - beta1. Check out this tabbed effect built into a lavender-colored modal window. Bootstrap 4.