Contain keeps the whole frame
Contain scales the source until every edge fits inside the destination. Nothing is cropped, but unused space may appear on two sides.
Cover fills the destination
Cover scales until the destination has no empty area, then crops the overflow. It is useful for cards and thumbnails when edge loss is acceptable.
Stretch changes geometry
Stretch forces both target dimensions independently. It is exact in pixels but circles can become ovals and people can look unnaturally wide or narrow.
Choose with a focal point in mind
Preview faces, text, logos, and product edges at the final aspect ratio. A mathematically centered crop is not always a visually safe crop.
Decide what should fill any empty area
Contain produces the requested pixel box even when the source ratio differs. The unused area is transparent for PNG or WebP and white for JPEG in this tool. That difference matters for logos, screenshots, and product cutouts that will appear on a colored page. Preview the exported file against the destination background instead of assuming transparent and white padding are interchangeable. If padding is unacceptable and cropping would remove important content, revise the target dimensions so their ratio is closer to the source.
Troubleshoot an unexpected crop
First compare the source width-to-height ratio with the destination ratio. A wide source placed in a square cover box must lose content at the left and right; a tall source loses content at the top and bottom. This tool centers that crop and does not guess a face or focal point. If the subject is off center, crop the original deliberately in an editor before resizing, or switch to contain. Use stretch only when geometric distortion is explicitly acceptable, such as an abstract texture.