Turn uncompressed BMP files into light JPGs. For BMPs exported by older software, this one conversion cuts the size dramatically.

Why BMP files are so large

BMP is the bitmap format that has shipped with Windows for decades. It is usually stored without compression: every pixel takes three or four bytes, whatever is in the picture. A 12-megapixel photo saved as a 24-bit BMP is therefore around 36 MB, simply from 12 million pixels times three bytes. Old scanners, legacy business software, some industrial cameras and screenshot utilities still produce BMPs, which is how they end up in inboxes and shared folders, far too heavy to send.

What changes in the conversion

Your browser decodes the BMP, and the picture is encoded as a JPG at the quality you choose: Smaller (62), Recommended (82) or High (94), or anywhere from 40 to 100 on the slider. Pixel dimensions stay the same. JPG is lossy, so very fine detail is approximated, which for photographs is rarely visible at Recommended. A 32-bit BMP with an alpha channel loses its transparency, since JPG has none; those areas become white.

When to choose something else

JPG is right for photographs. For screenshots, diagrams, charts and pixel art stored as BMP, PNG is the better target: it is lossless, keeps text crisp and still shrinks the file considerably. Switch the output format to PNG in that case. Converted files are named after the original with _conv and a .jpg extension, and a whole batch can be downloaded as one ZIP.

How to use it

1. Drop in your BMP files.
2. JPG is pre-selected as the output.
3. Check the savings and download.

Your files are never uploaded

Everything runs inside your browser. Because the image never reaches a server, we cannot store it or look at it. That difference matters when the file is company material or a personal photo.

Frequently asked questions

Why does it shrink so much?

BMP files are usually stored uncompressed — the file is essentially the raw pixels. JPG compresses the picture, so photo-like BMPs typically shrink to a small fraction of their size. The result list shows the exact before and after for each file.

Will the quality suffer?

At the recommended setting the difference is hard to spot. If in doubt, pick High quality — still far smaller than the BMP.

My BMP is a screenshot or diagram. Is JPG right?

Probably not. For sharp text and flat colours, PNG is lossless and usually small enough. Switch the output format on this page to PNG.

Can I convert back to BMP if a program needs it?

Yes. The Convert tool can also save BMP — 24-bit and uncompressed, for software that only reads that format.

Is it free?

Yes. No account, no payment, no usage limit.

Are my files uploaded?

No. Everything happens inside your browser. A page that is already open keeps working even if you go offline.

How many images at once?

There is no count limit. Speed depends on your own device, because your computer does the work rather than a server.