How to scale image to fit the container?

Question

I have an image list, I want images scaled into their containers which have same size. like this:

Answer 1

In 2017 you can use flex. Additionally you will get the images centered in the thumbnail container: updated fiddle

.thumbnail {
    height: 300px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    border: solid 1px blue;
}

.thumbnail img {
    max-width: 100%;
    max-height: 100%;
    display: block;
    margin: 0 auto;
    border: solid 1px red;
}