Resize an image

Fit inside scales the image until it fits within the width and height you give, keeping the original proportions, so one dimension usually ends up smaller than you asked for. Exact size forces both numbers, which stretches the image if the proportions don’t already match. Fit inside is what you want almost every time; exact size is for when a system demands specific pixel dimensions and won’t crop for you.

Because most tools scale in a single step. Drawing a 4000 pixel image straight into a 400 pixel box makes the browser sample roughly one pixel in ten and discard the rest, which produces shimmering edges and lost fine detail. This page halves the image repeatedly until it is close to the target, so each step averages neighbouring pixels. The difference is most obvious on text, thin lines and dense texture.

You can scale above 100%, but no detail is created by doing so. The extra pixels are interpolated from the ones already there, so the result is a larger, softer version of the same image. Genuine upscaling needs a model trained to invent plausible detail, which is a different kind of tool and can’t run usefully in a page like this one.

They are checked periodically and each was last confirmed in 2026-09, but platforms change their layouts without announcing it. Treat them as sensible defaults rather than as rules. In practice every major platform re-encodes whatever you upload anyway, so being close matters more than being exact, with one exception: aspect ratio, which is what determines whether you get cropped.

Scaling down discards pixels permanently, so yes, but that is the point and a well-resized image looks correct at its new size. The quality slider is separate: it controls how hard the result is compressed when it is saved. Resizing a JPG also means re-encoding it, which adds a small amount of compression loss on top, so work from the original when you can.