Image format
The BMP format
BMP is an uncompressed grid of pixels. BMP arrived with Windows 3.0 in 1990 as a simple way to store the pixels a screen shows.
When to use BMP
Use BMP only when a specific piece of software, a printer or an embedded device asks for it.
It is best for old software and hardware that only understands raw bitmaps, and it opens on Windows, macOS and most editors, but few websites accept it.
How to open it: Windows Photos, Paint and macOS Preview open BMP files directly.
| Full name | Windows Bitmap |
|---|---|
| Extensions | .bmp, .dib |
| MIME type | image/bmp |
| Introduced | 1990 |
| Compression | Uncompressed |
| Transparency | No |
| Animation | No |
| Support | Opens almost everywhere |
| Typical size | A 12-megapixel image is about 36 MB |
Good at
- No compression artefacts at all
- Trivial for old programs and microcontrollers to read
Not so good at
- Enormous files, often ten times a JPG
- Rarely accepted by websites and no good for email
The common mistake
BMP looks like a safe “raw” choice, but a single photo can run to tens of megabytes and most sites refuse it.
Convert BMP to another image format
Questions
What is a BMP file?
BMP (Windows Bitmap) is an uncompressed grid of pixels. BMP arrived with Windows 3.0 in 1990 as a simple way to store the pixels a screen shows.
How do I open a BMP file?
Windows Photos, Paint and macOS Preview open BMP files directly.
How do I convert BMP to another format?
Pick the target on this page, or open the Image Converter, drop the BMP file and choose a format. It converts in your browser, so nothing is uploaded.