BMP
Also known as: bitmap, bmp file, .bmp
BMP (.bmp), or bitmap, is an old Windows image format that usually stores pixels with little or no compression. The result is very large files — often many times the size of the same image as JPEG or PNG — so it is rarely a good way to keep photos.
- Old Windows bitmap format
- Little or no compression — very large files
- PNG gives the same quality far smaller
Why BMP files are so large
A classic BMP records each pixel’s color directly with no meaningful compression. A photo that would be a couple of megabytes as JPEG, or a few as PNG, can balloon to many times that size as a BMP carrying the same content.
Because it is simple and lossless, BMP shows no compression artifacts — but PNG offers the same lossless quality with real compression, making BMP almost always the wasteful choice today.
What to do with BMPs
BMP turns up mostly in older Windows software and exported graphics. If you find BMP files taking space, converting them to PNG (for lossless) or JPEG (for photos) shrinks them substantially with no visible loss.