BMP to JPG Converter
Convert BMP images to JPG format in your browser. Reduces file size significantly. No upload, no watermark, no signup.
Drop your images here
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Why BMP files are enormous
BMP stores raw pixels with essentially no compression. Three bytes per pixel, no encoding, no cleverness. A 1920 by 1080 image is about 6 MB regardless of what is in it, whether that is a photograph or a solid blue rectangle.
That is why converting to JPEG produces such a dramatic size reduction, often 95 percent or more. The number looks impressive but it mostly reflects how inefficient the source format was, not how good the conversion is.
Where BMP files come from
Usually older Windows software, scanner drivers, medical or scientific instruments, and some industrial equipment that has not been updated in twenty years. Occasionally a screenshot from an old tool. They are rarely something anyone chose deliberately.
More detail
What the conversion costs you
BMP is lossless, so this is the first time the image has been compressed lossily. That means artefacts appear where there were none. On a photograph at quality 0.85 that is invisible. On a screenshot of text, or a scanned document with fine line work, JPEG rings around every edge and the result can be noticeably worse than the original.
If the BMP is a scan or a screenshot rather than a photograph, PNG or WebP is the better target: still a large size reduction, but without introducing artefacts into content that has hard edges.
Transparency
Most BMP files have no alpha channel at all, and JPEG could not store one anyway. If you happen to have one of the rare BMP variants that does carry alpha, it is composited onto white during conversion.
Questions
Why is the JPEG so much smaller?
Because BMP stores raw uncompressed pixels, roughly three bytes each, with no encoding at all. Almost any compressed format will be a fraction of the size. A 95 percent reduction is normal and says more about BMP than about JPEG.
Is this the first time the image loses quality?
Yes. BMP is lossless, so the source has never been compressed. JPEG is the first lossy step, which means artefacts appear where previously there were none.
My BMP is a scanned document. Should I still use JPEG?
Probably not. JPEG rings around the hard edges of text and line work, which is exactly what a scan is made of. PNG or WebP will still be far smaller than the BMP without introducing that damage.
Are the files uploaded?
No. The decode and re-encode both happen on a canvas in your browser, and nothing carrying the image is transmitted.