How to use it
- Add your images.
- If any have transparency, pick the colour to fill it with.
- Download the BMP files.
What you get
The files are uncompressed 24-bit Windows bitmaps, the most widely readable kind of BMP. They are stored bottom-up with each row padded to a multiple of four bytes, as the format expects. The resolution tag is set to 72 DPI, which most software ignores anyway.
Expect big files. Every pixel takes three bytes, so a 12 MP photo becomes a 36 MB bitmap. If the software on the other end also accepts PNG, use PNG instead: it is just as lossless and much smaller.
Making BMPs for small devices
Embedded displays and hobby electronics often want a specific size. Resize the image first with the image resizer, save it as PNG to avoid compressing twice, then convert that to BMP here.
JPG and BMP compared
| JPG | BMP | |
|---|---|---|
| First released | 1992 | 1985 |
| Compression | Lossy | Usually none |
| Transparency | No | Rarely |
| Animation or pages | No | No |
| Best for | Photos for sharing, email and print | Older Windows software and devices |
| Support | Universal | Most desktop software |
Questions people ask
Does converting JPG to BMP improve quality?
No. It stores the decoded JPG pixels without compression. Any JPG artefacts remain.
Can I make 8-bit or 1-bit BMPs?
This tool writes 24-bit files only, which nearly all BMP readers accept.
Why is the BMP so big?
Standard BMP files are uncompressed: width × height × 3 bytes, plus a small header.