<div class="container">
  <h1 class="display-4 text-center mb-4">Bootstrap Modals</h1>
  
  <div class="row mb-4">
    <div class="col text-center">
      <h3>The Basic Modal</h3>
      <a href="#" class="btn btn-lg btn-success" data-toggle="modal" data-target="#basicModal">Click to open Modal</a>
    </div>
  </div>
  
  <div class="row mb-4">
    <div class="col text-center">
      <h3>The Large Modal</h3>
      <a href="#" class="btn btn-lg btn-primary" data-toggle="modal" data-target="#largeModal">Click to open Modal</a>
    </div>
  </div>
  
  <div class="row">
    <div class="col text-center">
      <h3>The Small Modal</h3>
      <a href="#" class="btn btn-lg btn-danger" data-toggle="modal" data-target="#smallModal">Click to open Modal</a>
    </div>
  </div>
</div>

<!-- basic modal -->
<div class="modal fade" id="basicModal" tabindex="-1" role="dialog" aria-labelledby="basicModal" aria-hidden="true">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header">
        <h4 class="modal-title" id="myModalLabel">Basic Modal</h4>
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">&times;</span>
        </button>
      </div>
      <div class="modal-body">
        <h3>Modal Body</h3>
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
        <button type="button" class="btn btn-primary">Save changes</button>
      </div>
    </div>
  </div>
</div>

<!-- large modal -->
<div class="modal fade" id="largeModal" tabindex="-1" role="dialog" aria-labelledby="basicModal" aria-hidden="true">
  <div class="modal-dialog modal-lg">
    <div class="modal-content">
      <div class="modal-header">
        <h4 class="modal-title" id="myModalLabel">Large Modal</h4>
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">&times;</span>
        </button>
      </div>
      <div class="modal-body">
        <h3>Modal Body</h3>
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
        <button type="button" class="btn btn-primary">Save changes</button>
      </div>
    </div>
  </div>
</div>

<!-- small modal -->
<div class="modal fade" id="smallModal" tabindex="-1" role="dialog" aria-labelledby="basicModal" aria-hidden="true">
  <div class="modal-dialog modal-sm">
    <div class="modal-content">
      <div class="modal-header">
        <h4 class="modal-title" id="myModalLabel">Small Modal</h4>
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">&times;</span>
        </button>
      </div>
      <div class="modal-body">
        <h3>Modal Body</h3>
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
        <button type="button" class="btn btn-primary">Save changes</button>
      </div>
    </div>
  </div>
</div>

External CSS

  1. https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-beta.2/css/bootstrap.css

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js
  2. https://unpkg.com/popper.js
  3. https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-beta/js/bootstrap.min.js