Bitmap Image File
BMP is an uncompressed (or minimally compressed) raster format originally built for Windows. Every pixel is stored directly, so files are lossless but often very large.
Extensions
.bmp
MIME type(s)
image/bmp, image/x-ms-bmp
Compression
Uncompressed
Transparency
Not supported
Advantages
- Lossless — no compression artifacts
- Simple, well-documented file structure
Disadvantages
- Very large file sizes compared to PNG or JPG
- Poor support outside of Windows-native applications
- Rarely used for the modern web
Common uses
- Legacy Windows applications
- Simple raster image storage where compression isn't a concern
How to open a BMP file
Opens in Windows Photos, most desktop image viewers, and all modern browsers.