with the class. You can try to run the following code to make the size of a button extra small Example Live Demo For example, for a half-width "block button", use .col-6. "glyphicon glyphicon-ok form-control-feedback", "glyphicon glyphicon-warning-sign form-control-feedback", "glyphicon glyphicon-remove form-control-feedback", , , , , , , // See https://github.com/twbs/bootstrap/issues/4885; IE9+, mixins for generating more semantic layouts, Screen reader and keyboard navigation content, Collapsed to start, horizontal above breakpoints, Applies the hover color to a particular row or cell, Indicates a successful or positive action, Indicates a neutral informative change or action, Indicates a warning that might need attention, Indicates a dangerous or potentially negative action, Ruby gem code (Sass configuration, Rails and Compass integrations), Converter scripts (turning upstream Less to Sass). The short answer is: use the Bootstrap button size classes to add to the button element as given below: .btn-lg .btn-md .btn-sm .btn-xs(Removed in Bootstrap 4 but you can use with Bootstrap 3 given below) Bootstrap provides many useful classes to create a button and use on your website. Be sure to escape any angle brackets in the code for proper rendering. To increase icon sizes relative to their container, use fa-xs , fa-sm, fa-lg ( 33% increase), or use literal sizes (to scale it from 1x to 10x) fa-2x, fa-3x , fa-4x, fa-5x, fa-6x, fa-7x , fa-8x, fa-9x, fa-10x . Fancy larger or smaller buttons? Furthermore, .invisible can be used to toggle only the visibility of an element, meaning its display is not modified and the element can still affect the flow of the document. Step 1 : Reference the Bootstrap StyleSheet in inside "<head>" tag of your ASP.NET page : <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4../css/bootstrap.min.css" > Step 2 : Reference the CssClass property of your ASP.NET Button like : <asp:Button runat="server" Text="btn-primary" CssClass="btn btn-primary" /> Forget adding class="clearfix" to any element and instead add the .clearfix() mixin where appropriate. For