Resize image

The right dimensions for every platform

Every platform has its sweet spot: an Instagram square post looks best at 1080×1080 pixels, a Story or Reel at 1080×1920, and a YouTube thumbnail at 1280×720. Using the correct size up front prevents awkward auto-cropping and keeps your image sharp instead of letting the platform recompress it.

Fit or stretch?

With "keep aspect ratio" turned on, your image is scaled to fill the target size and cropped at the center if needed, the same approach social networks use. Turn it off and the image is stretched to exactly the width and height you enter, which can distort it if the proportions don't match.

Shrinking works, enlarging hardly ever

Reducing an image throws pixels away, and the result is clean: from 4000 to 1000 pixels the software averages neighbouring points and the photo stays sharp. Enlarging, instead, asks it to invent information that is not there: the new pixels are calculated by interpolation, and the result is softer than the original, never more detailed.

It is why a low-resolution photo is not «improved» by taking it to larger dimensions: you get the same detail spread over more pixels, plus a heavier file. Upscalers based on neural networks do something different, that is they imagine plausible detail: excellent for a family photo and never for a document or a piece of evidence.

The sizes that actually matter

For social media: square post 1080 by 1080, story and reel 1080 by 1920, video cover 1280 by 720. For a web page it is best to export at twice the size the image will be displayed at, because of high-density screens, and in any case stay below 2000 pixels a side for full-width photos.

For print the sum is different: about 300 pixels per inch are needed, so a photo printed at 10 by 15 centimetres wants at least 1200 by 1800 pixels. For an email attachment or a form, 1600 pixels on the long side is almost always enough and cuts the size tenfold.

Fit or crop, and why the two are not the same

If the source and destination formats have different proportions, something has to give. Cropping keeps the proportions right and removes the edges: it is what social platforms do, and it is why a vertical photo uploaded as a square post loses the head or the feet. Stretching keeps everything but lengthens or squashes, and on a face it shows immediately.

The third route is adding bars, that is coloured borders completing the format without cutting or distorting. It is the right choice when the image is a chart, a diagram or a document, where cropping would mean losing information.

The things lost along the way

The metadata, which resizing often does not carry over: if the capture date or the settings matter, check afterwards. And the rotation: a photo taken vertically with a phone carries an orientation flag, and some programs apply it while others do not, which is why a resized photo sometimes comes out lying on its side.

Finally it is worth remembering that resizing recompresses: if the source file was already a JPEG, the new one goes through compression a second time. So it is better to start from the original and not from a copy that has already been through two or three programs.

Nearby tools

For size there are Compress image and Compress to a target size, for format Convert image. To see how big a photo is Photo dimensions and info, and for specific cases Passport photo and Round photo.