How to set max width of an image in CSS

Question

On my website I would like to display images uploaded by user in a new window with a specific size (width: 600px). The problem is that the images may be big. So

Answer 1

The problem is that img tag is inline element and you can't restrict width of inline element.

So to restrict img tag width first you need to convert it into a inline-block element

img.Image{
    display: inline-block;
}