Vertically centering Bootstrap modal window

Question

I would like to center my modal on the viewport (middle) I tried to add some css properties

 .modal { position: fixed; top:50%; left:50%; }   

Answer 1

This is what I did for my app. If you take a look at the following classes in the bootstrap.css file .modal-dialog has a default padding of 10px and @media screen and (min-width: 768px) .modal-dialog has a top padding set to 30px. So in my custom css file I set my top padding to be 15% for all screens without specifying a media screen width. Hope this helps.

.modal-dialog {
  padding-top: 15%;
}

Answer 2

Simply add the following CSS to you existing one,It works fine for me

.modal {
  text-align: center;
}
@media screen and (min-width: 768px) {
    .modal:before {
      display: inline-block;
      vertical-align: middle;
      content: " ";
      height: 100%;
    }
}
.modal-dialog {
  display: inline-block;
  text-align: left;
  vertical-align: middle;
}

Answer 3

Another CSS answer to this question...
This solution uses CSS only to achieve the desired effect while still maintaining the ability to close the modal by clicking outside of it. It also allows you to set .modal-content height and width maximums so that your pop-up won't grow beyond the viewport. A scroll will automatically appear when the content grows beyond the modal size.

note:
The Bootstrap recommended .modal-dialog div should be omitted in order for this to work properly (doesn't seem to break anything). Tested in Chrome 51 and IE 11.

CSS Code:

.modal {
   height: 100%;
   width: 100%;
}

.modal-content {
   margin: 0 auto;
   max-height: 600px;
   max-width: 50%;
   overflow: auto;
   transform: translateY(-50%);
}

EDIT: The .modal-dialog class allows you to choose whether or not a user can close the modal by clicking outside of the modal itself. Most modals have an explicit 'close' or 'cancel' button. Keep this in mind when using this workaround.

Answer 4

Yet another CSS solution. Does not Work for popups that are bigger than the view port.

.modal-dialog {
    position: absolute;
    right: 0;
    left: 0;
    margin-top: 0;
    margin-bottom: 0; 
}
.modal.fade .modal-dialog {
    transition: top 0.4s ease-out;
    transform: translate(0, -50%);
    top: 0;
}
.modal.in .modal-dialog {
    transform: translate(0, -50%);
    top: 50%;
}

In .modal-dialog class overriding the position to absolute(from relative) and centering the content right:0, left: 0

In .modal.fade .modal-dialog , .modal.in .modal-dialog setting the transition animation over top rather than on translate.

margin-top moves the popup slightly below the center in case of small popup and in case of long popups, the modal is stuck with header. Hence margin-top:0, margin-bottom:0

Need to further refine it.

Answer 5

e(document).on('show.bs.modal', function () {
        if($winWidth < $(window).width()){
            $('body.modal-open,.navbar-fixed-top,.navbar-fixed-bottom').css('marginRight',$(window).width()-$winWidth)
        }
    });
    e(document).on('hidden.bs.modal', function () {
        $('body,.navbar-fixed-top,.navbar-fixed-bottom').css('marginRight',0)
    });

Answer 6

I think this is a bit cleaner pure CSS solution than Rens de Nobel's solution. Also this does not prevent from closing the dialog by clicking outside of it.

http://plnkr.co/edit/JCGVZQ?p=preview

Just add some CSS class to DIV container with .modal-dialog class to gain higher specificity than the bootstraps CSS, e.g. .centered.

HTML

<div class="modal fade bs-example-modal-lg" tabindex="-1" role="dialog" aria-labelledby="myLargeModalLabel">
  <div class="modal-dialog centered modal-lg">
    <div class="modal-content">
      ...
    </div>
  </div>
</div>

And make this .modal-dialog.centered container fixed and properly positioned.

CSS

.modal .modal-dialog.centered {
    position: fixed;
    bottom: 50%;
    right: 50%;
    transform: translate(50%, 50%);
}

Or even simpler using flexbox.

CSS

.modal {
    display: flex;
    align-items: center;
    justify-content: center;
}