By ShinobiTools Team · Last updated: August 2026
Change a photo's width and height, or knock it down to a percentage of what it was. Proportions stay locked unless you unlock them, and it all happens in your browser.
Type an exact width if you have been given one — 1080 px for an Instagram post, 512 px for an app icon, 800 px for a blog image. Leave "keep the proportions" ticked and the height follows on its own, so the photo never comes out stretched. If you genuinely need a fixed width and height that do not match the original shape, untick it and accept the squash, or crop to the right shape first, which is what you almost always actually want.
If you are just trying to make a file lighter, think in percentages instead. Halving the width leaves a quarter of the pixels, which is a far bigger saving than any quality setting will give you.
Plenty of people search for resizing an image "in KB", and that is worth untangling, because the two knobs do different jobs. Pixels are how big the picture is. Kilobytes are how heavy the file is. Making the pixels smaller does make the file lighter, but you cannot aim at a KB number by dragging a width around — you would be guessing and re-exporting all afternoon.
So if the requirement is a file size, use the compress page, which takes a KB target and works the settings out for you. Use this page when the requirement is a dimension. And when a form demands both, do it in that order: resize to the dimension here, then compress to the size there.
Most resizing is somebody else's rule, not a preference. These are the ones that come up over and over, and none of them need a photo editor.
Making a photo bigger is a different job. Stretching pixels up in a browser just makes them softer; rebuilding the missing detail needs a model, which is what the upscaler on this site is for.
Making a photo smaller is nearly lossless if you do it once, in one step, at high quality — which is what this tool does. Quality gets lost when you shrink, save, shrink again, or when you enlarge a photo beyond its real detail.
That is compressing rather than resizing. Use the compress page, give it your KB target, and it finds the settings for you.
Yes, by default. Type a width and the height follows. Untick "keep the proportions" if you deliberately want to stretch it.
You can set a larger width here, but browser scaling only stretches the pixels you already have. To genuinely add detail, use the AI upscaler, which rebuilds it.
No. The resizing happens in your browser with the canvas API, so the file never leaves your device.
Anything your browser can display: JPG, PNG, WEBP, GIF and BMP. HEIC from an iPhone usually needs saving as JPG first, because most browsers cannot decode it.