How to resize an image without distorting it
The most common mistake we see in store photos is a product that looks wider or taller than it really is, because it was resized without keeping its proportions. The fix is simple once you see what is going on.
The key: width to height ratio
Every image has a fixed ratio between its width and height. A 4000 × 3000 pixel photo has a ratio of 4 to 3. Change the width on its own and leave the height alone, and the ratio changes, so everything in the picture stretches. A round mug turns oval and a face looks thinner.
Locking the aspect ratio solves this automatically. You type one number and the other is worked out so the shape stays the same.
A photo measuring 400 × 300 pixels, with the ratio locked.
You type a width of 200, and the height becomes 150 on its own.
The result is 200 × 150, exactly the same shape, just smaller.
Step by step
- Open the Image resizer and choose your photo.
- Check that the aspect-ratio lock is on. It is by default.
- Type the width or height you want in pixels, and the other side is calculated for you.
- Choose the output format. “Keep” saves in the original format. Then download.
When you need a different shape
Sometimes you need a square image from a rectangular photo. Locking the ratio is not enough here, and you have to decide how to handle the difference:
- Contain: the whole photo fits inside the square, with empty bands on two sides.
- Cover: the photo fills the square completely, and whatever sticks out is cropped.
- Stretch: the photo is forced into the new size and distorts. You rarely want this for product photos.
If you want to choose exactly what gets cut, use the Image cropper, pick the 1:1 ratio and move the crop box over the part that matters.
Enlarging does not create detail
Making a small photo bigger cannot bring back detail that was never captured. The new pixels are calculated from their neighbors, so the picture looks softer. That is why the tool warns you when you enlarge beyond the original size. If quality matters, the only real fix is a larger original.
About the preset sizes
The tool offers common sizes as a starting point, but they are not the official specification of any platform. Platforms change their sizes from time to time, so check yours and edit the numbers. After resizing, run the photo through the Image compressor to shrink the file as well.
Common questions
Does shrinking a photo lower its quality?
Shrinking keeps the shape well. Saving as JPEG or WebP gives up some detail, depending on the quality you choose.
Does it support iPhone HEIC photos?
No. Supported formats are JPEG, PNG and WebP. HEIC, animated GIF and SVG are not supported.
Is my photo uploaded?
No, processing happens inside your browser on your device.