Why this tool is different
BMP stores every pixel uncompressed, which is why a modest image can run to tens of megabytes. Converting to JPG typically cuts that by 95 percent or more with no visible difference — and unlike BMP, the result opens on a phone.
How it works
- 1
Add one or more BMP files.
- 2
Choose a JPG quality.
- 3
We decode the bitmap and encode JPG.
- 4
Download individually or as a ZIP.
What to watch out for
The size difference is enormous
A 1920×1080 BMP is roughly 6MB regardless of content. The same image as a quality-85 JPG is usually well under 300KB.
Where BMPs come from
Old Windows software, scanners, screen captures and some medical or scientific tools still write BMP. It is rarely the right format to keep anything in.
Transparency
Most BMP files have no transparency. If yours does, it is flattened onto the background colour you choose.
Frequently asked questions
Why are BMP files so large?
BMP stores each pixel literally, with no compression. File size depends only on dimensions and colour depth, not on the image content.
Will I lose quality converting BMP to JPG?
JPEG is lossy, so some information is discarded. At quality 85 or above it is very hard to see, and the file is a small fraction of the size.
Should I use PNG instead?
For screenshots, diagrams and anything with sharp edges or text, yes — PNG is lossless and still far smaller than BMP. For photographs, JPG wins on size.
Are my files uploaded to a server?
No. The conversion runs in JavaScript and WebAssembly inside your own browser. Open your devtools, switch to the Network tab and run a conversion — there is no upload request to see. Closing the tab clears the working session.