What is a BMP file?
BMP is an uncompressed bitmap format from early Windows. Because it stores every pixel raw, BMP files are enormous (a 12 megapixel photo is about 36 MB) but they are trivially simple, so old software, microcontrollers, label printers and some games still require them.
| Full name | Bitmap Image File |
|---|---|
| File extensions | .bmp, .dib |
| MIME type | image/bmp |
| Introduced | 1990 |
| Compression | None (uncompressed) |
| Transparency | Rarely supported |
| Animation | No |
| Typical file size | Huge |
| Best for | legacy Windows software, embedded devices and some printers |
| Compatibility | Windows apps and most editors; inefficient for the web |
How to open a BMP file
Windows
Opens in Photos and Paint (BMP is a native Windows format).
Mac
Preview opens BMP files.
iPhone and iPad
Not reliably viewable; convert to JPG or PNG first.
Android
Many gallery apps open it, but sharing and uploading usually fail.
If none of these work, convert the file to a more widely supported format with one of the tools below.
Convert BMP files
Convert other files to BMP
BMP compared with other formats
- BMP vs PNG: PNG stores the same pixels as BMP in a fraction of the space. Only use BMP when a program specifically requires it.
Frequently asked questions
What is a BMP file?
BMP is an uncompressed bitmap format from early Windows. Because it stores every pixel raw, BMP files are enormous (a 12 megapixel photo is about 36 MB) but they are trivially simple, so old software, microcontrollers, label printers and some games still require them.
How do I open a BMP file on Windows?
Opens in Photos and Paint (BMP is a native Windows format).
How do I open a BMP file on a Mac?
Preview opens BMP files.
Is BMP lossy or lossless?
BMP is lossless or uncompressed, so no detail is lost when saving.
Does BMP support transparency?
Rarely supported. Use PNG or WebP if you need a transparent background.
How do I convert BMP to another format?
Use one of the free converters on this page, for example BMP to JPG, BMP to PNG, BMP to WebP. Files are converted in your browser without being uploaded.