extreme_dimensions

Twenty-five tiny files that claim to be enormous pictures. A 1x65535 GIF is only 463 bytes, and a 30000x30000 PNG is 109 KB, yet opening one at full size would need several gigabytes of memory. These test pixel-flood protection: a web app that resizes uploads can be crashed by a small file with a huge canvas. The limits shown are the real maximum sizes of each format, such as 65535 for GIF, 16383 for WebP and 65500 for the JPG here. Many tools refuse these files on purpose. Check that yours rejects them safely and does not run out of memory.