Resize images without uploading them

Resizing happens right before a picture goes somewhere: an application form, an avatar, a marketplace listing, a post. That moment of publication is the moment a photo's hidden data becomes everybody's, so resizing is worth pairing with an EXIF check rather than treating as a purely cosmetic step.

The ceilings are real and they are a consequence of the arrangement. Because the resize runs on your own machine's memory rather than on a server, a very large camera file or a stitched panorama can exceed roughly 32 megapixels in total or 8192 pixels on a side. When that happens, reduce in two passes, or crop first and then resize what is left.

Decide the target properly. Upscaling invents nothing: enlarging a small image gives you a bigger, softer version of the same information. Keep the aspect ratio unless you specifically want distortion, and choose PNG when the picture contains text or flat colour, because JPEG artefacts cluster around sharp edges exactly where letters are.

Resizing typically produces a new image without the original camera data attached, but do not take that on trust for a photo you are about to publish. Resize, then open the result in the EXIF viewer and confirm. While you are there, the network panel will show you that neither the original nor the result went anywhere.