JSFiddle - React, Tailwind, and code Playground

HTML

<p>image is set to 100x100 pixels!</p>

<img id="draggable" src="http://3.bp.blogspot.com/-mzu6Wc9peP4/UFpJSiVDqnI/AAAAAAAAAzM/kBJDl9jAiAM/s1600/lol_cat1.jpeg" />

<div id="dim"></div>

CSS

#draggable {height: 100px; width: 100px;}

JavaScript

var img     = document.getElementById('draggable'),
    new_img = new Image();

new_img.onload = function() {
    var img_width  = this.width,
        img_heigth = this.height;
    
    document.getElementById('dim').innerHTML = 'Original dimensions are : ' + img_width + 'x' + img_heigth + ' pixels';
}

new_img.src = img.src;