Sample BMP image for testing — free, CC0

BMP is the Windows bitmap format: a small header followed by pixels, usually uncompressed. It is simple to write and still appears in scanners, legacy software and clipboard exports, so image pipelines are expected to accept it.

bmp/24bit-256x256.bmp is the loremfile colour-bar test card at 256x256 pixels, stored as uncompressed 24-bit BMP. The card has a border, a centre cross and a label giving the dimensions and mode, so a decoder that flips rows or swaps colour channels shows it immediately. BMP usually stores rows bottom-up and pixels in blue-green-red order, and both are classic sources of upside-down or blue-tinted images.

Use it to test image upload forms, thumbnail generators and converters. Because the file is uncompressed, its size follows directly from its dimensions, which also makes it handy for checking that a resize or conversion step really ran. Compare it with the same test card as PNG or TIFF.

curl -O https://loremfile.dev/bmp/24bit-256x256.bmp

<img src="https://loremfile.dev/bmp/24bit-256x256.bmp" alt="">