How to vertically center modal?

Question

I want to vertically center a modal. I searched a lot on Google but found nothing helpful. Here is my code:

 function inactive(id, ths) {
   $("#confirmation").modal("show");
 }

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="modal fade bs-example-modal-sm" id="confirmation" tabindex="-1" role="dialog" aria-labelledby="mySmallModalLabel">
  <div class="modal-dialog modal-sm" role="document">
    <div class="modal-content">
      <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span>
        </button>
        <h4 class="modal-title">Are you sure you want to inactivate it?</h4>
      </div>
      <div class="modal-body">
        <div class="form-group">
          <input type="text" class="form-control" name="captcha" id="cval" placeholder="enter captcha">
        </div>
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal">No</button>
        <button type="button" class="btn btn-primary" id="yes">Yes</button>
      </div>
    </div>
  </div>
</div>

How can I center it vertically?

Answer 1

Not tested but you can try this

.yourElement{
  position: relative;
  top: 50%;
  transform: translateY(-50%);
}

Answer 2

There is a specific bootstrap class (v4.1) for this:

Add .modal-dialog-centered to .modal-dialog to vertically center the modal.

Source: https://getbootstrap.com/docs/4.1/components/modal/#vertically-centered

Answer 3

As it looks as a bootstrap modal, Checkout this Fiddle (jsFiddle).

Try

.modal-dialog {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) !important;
}

Hope this helps!