A Pen by Chris Robinson.

index.html

<figure>
    <img src="http://contempographicdesign.com/wp-content/uploads/2013/11/super-happy-cat.jpg" />
</figure>

style.css

figure {
    overflow: hidden;
}
				
figure img {
    -webkit-transition: -webkit-transform 0.5s ease;
    -moz-transition: -moz-transform 0.5s ease;
    -o-transition: -o-transform 0.5s ease;
    -ms-transition: -ms-transform 0.5s ease;
    transition: transform 0.5s ease;
    -webkit-backface-visibility: hidden;
    -moz-backface-visibility: hidden;
    -ms-backface-visibility: hidden;
}
					
figure img:hover {
    -webkit-transform: scale(1.1, 1.1);
    moz-transform: scale(1.1, 1.1);
    -o-transform: scale(1.1, 1.1);
    -ms-transform: scale(1.1, 1.1);
    transform: scale(1.1, 1.1);
}

Ultra-Simple-CSS3-Image-Zoom-on-Hover.markdown

Ultra Simple CSS3 Image Zoom on Hover

A Pen by Chris Robinson on CodePen.

License.