Why are BMP files so big?

Because they store every pixel with no compression. A 12-megapixel image is about 36 megabytes as a BMP and might be one and a half as a JPG.

Some, since JPG is lossy — but the source is uncompressed, so at a high quality setting the difference is not visible while the file is a fraction of the size.

Free converter

BMPJPG

BMP to JPG Converter

BMP stores every pixel completely uncompressed, which makes a modest image absurdly large — a phone-sized photo can run past twenty megabytes. Converting to JPG typically cuts it by a factor of twenty or more with no visible difference at all.

Download for Windows

Windows 10/11 (x64) · Free · No account

Drop in your files — JPGs land in the folder you pick — usually a tiny fraction of the BMP's size.

Why convert

Why convert BMP to JPG

BMP is Windows' oldest image format and it applies essentially no compression. Files that come out of old software, scanning utilities and industrial equipment are frequently BMP, and they are impractical to store or send. JPG is smaller by an enormous margin and opens everywhere.

Output from old Windows software or industrial equipment.
Getting an uncompressed image down to an emailable size.
Converting a folder of legacy images in one pass.
Making BMP files usable on the web, which will not display them.

How it works

Convert BMP to JPG in a few clicks

1
Drop your BMP files in
One or a folder full. They will be large; there is no size cap.
2
Choose JPG and a quality
Even a high quality setting produces a dramatically smaller file than the BMP.
3
Get the JPGs back
In the folder you chose, BMPs untouched.

The details

BMP to JPG, at a glance

Engine: sharp (libvips)
Output: JPG
Typical saving: Very large — BMP is essentially uncompressed
Where it runs: Your own PC — nothing is uploaded
Limits: None — no file count, no file-size cap, no watermark
Platform: Windows 10/11 (x64)

Questions