And Now For Something Completely Different: Resizable Bootstrap Modals

(Update: Now with better overflow handling.)

I have been doing more CSS + JS as I would have liked these past months. I am still a newbie but today I did something which I am happy enough about to make it into a short blog post.

Twitter’s Bootstrap CSS framework is a nice basis to get your web page going. It also has modal windows. JQuery has the resizable function which allows to add resize handles to any div. In order to make this work with a Bootstrap modal I did the following things:

1. Slightly change the positioning of the jQuery resize handles so they do not force scrollbars on the Bootstrap modal and do not add a weird border:

.ui-resizable-s {
  bottom: 0;
.ui-resizable-e {
  right: 0;

2. A little bit of JS magic to properly reposition the modal once it has been resized:

$(".modal").on("resize", function(event, ui) {
    ui.element.css("margin-left", -ui.size.width/2);
    ui.element.css("margin-top", -ui.size.height/2);
    ui.element.css("top", "50%");
    ui.element.css("left", "50%");

    $(ui.element).find(".modal-body").each(function() {
      $(this).css("max-height", 400 + ui.size.height - ui.originalSize.height);

Just look at the Bootstrap modal's margin in Firebug or something similar to understand the first two statements. The top and left values are to fix the positioning in Opera. The last statement is to also resize the modal body for proper overflow handling.

Now just enable resize on all modals or on whatever modal you want: