Add CSS transition effect for both the width and height property

To add transition effect for width and height property of an element, you can try to run the following code


Live Demo

<!DOCTYPE html>
         div {
            width: 150px;
            height: 150px;
            background: blue;
            transition: width 3s;
         div:hover {
            width: 250px;
            height: 250px;
      <h1>Heading One</h1>
      <p>Hover over the below box to change its width and height.</p>