How this works
Enter a width, a height, or both — with "keep aspect ratio" on, giving just one dimension calculates the other automatically so nothing gets stretched or squashed. Giving both fits the image inside that box while preserving its proportions, rather than forcing an exact stretch.
Common questions
What happens if I turn off "keep aspect ratio"?
The image stretches to exactly the width and height you enter, even if that distorts the proportions — useful only when you specifically need an exact pixel size regardless of shape.
Can I make an image bigger than the original?
Yes, but upscaling just stretches existing pixels rather than adding real detail — it'll look softer than a photo actually taken at that resolution.