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>