What is clearfix in Bootstrap

Clearfix is a CSS solution to deal with a bug that occurs when two floated elements are stacked next to each other. Bootstrap provides a special class to solve this problem.

Easily clear floats by adding .clearfix to the parent element. Can also be used as a mixin.

Use in HTML:

        
            
          <div class="clearfix">...</div>

The mixin source code:

        
            
          @mixin clearfix() {
            &::after {
              display: block;
              clear: both;
              content: "";
            }
          }

Use the mixin in SCSS:

        
            
          .element {
            @include clearfix;
          }

The following example shows how the clearfix can be used. Without the clearfix the wrapping div would not span around the buttons which would cause a broken layout. 

        
            
          <div class="bg-info clearfix">
            <button type="button" class="btn btn-secondary float-start">
              Example Button floated left
            </button>
            <button type="button" class="btn btn-secondary float-end">
              Example Button floated right
            </button>
          </div>