How do I fit an image (img) inside a div and keep the aspect ratio?

Question

I have a 48x48 div and inside it there is an img element, I want to fit it into the div without losing any part, in the mean time the ratio is kept, is it achievable using h

Answer 1

I was having a lot of problems to get this working, every single solution I found didn't seem to work.

I realized that I had to set the div display to flex, so basically this is my CSS:

div{
display: flex;
}

div img{ 
max-height: 100%;
max-width: 100%;
}