Windows Bitmap is the standard graphics file format used by Microsoft Windows. Windows Bitmap files can have 2, 16, 256, or 16.7 million (24-bit) colors. Most Windows Bitmap files are not compressed. You can save 16- and 256-color images in a compressed format, but some applications cannot read the compressed files.

This format preserves the quality and detail of the images well.

The default file extension for Windows Bitmap files is BMP. Occasionally you may see files with the extension DIB and RLE. Windows Run-Length Encoded (RLE) is a variation of the BMP file format. The RLE format features modest image compression, so it may have a smaller file size, depending on the photo.

RLE files come in either in 16 or 256 colors. This format has two primary uses in Windows—as wallpaper and logo screens.