bootstrap 4 button extra small code example
Example 1: large button in bootstrap
<button type="button" class="btn btn-primary btn-lg">Large button</button>
<button type="button" class="btn btn-primary">Large button</button>
<button type="button" class="btn btn-primary btn-sm">Large button</button>
<button type="button" class="btn btn-primary btn-lg btn-block">Block level button</button>
Example 2: bootstrap 4 button size
<button type="button" class="btn btn-primary btn-lg">Large button</button>
<button type="button" class="btn btn-secondary btn-sm">Small button</button>