Why are BMP files so enormous?
BMP — the bitmap format built into Windows since the 1990s — stores every pixel with zero compression. A single 1920 by 1080 screenshot saved as BMP weighs about 6 megabytes; a scanned document can easily pass 50. That was tolerable when images lived on a local hard drive, but today those files are a liability: they bounce off email attachment limits, take forever to upload, and devour phone storage. The image data itself is perfectly good — it is just wrapped in the most wasteful packaging imaginable. Converting BMP to JPG keeps every pixel while replacing the packaging with smart compression, which is why the size difference is so dramatic.
How much space does JPG actually save?
More than any other conversion on this site. Because BMP applies no compression at all, JPEG typically shrinks the file by 90 to 97 percent — at high quality settings where the result looks identical on screen. A 15 MB BMP screenshot becomes a 400–700 KB JPG; a 50 MB scan becomes a couple of megabytes. The quality slider defaults to 90%, which preserves fine text and detail beautifully; drop to 80% for casual sharing and you will barely see a difference. The result banner shows your exact savings for every file, and first-time users are usually stunned by the number.
How to convert a BMP file to JPG
All modern browsers decode BMP natively, so the tool above opens your file directly. Drag the BMP into the dashed box, or click it to browse your device — the image appears instantly and conversion starts automatically. Adjust the quality slider if you like; the output re-encodes live as you drag. The after preview shows the JPG next to the original with exact dimensions and file sizes, plus a banner with your real savings. Click download to save your .jpg file. No uploads, no queues, no watermarks — everything runs on your device. Dimensions are preserved exactly: a 1920 by 1080 BMP becomes a 1920 by 1080 JPG.
When should you keep the BMP?
Honestly? Almost never for everyday use. The one legitimate reason is archival: BMP is uncompressed, so it is a bit-perfect master with no compression artifacts. If you are preserving a scan as a long-term original, keep one BMP copy tucked away. For everything else — emailing, uploading, printing, sharing — the JPG is superior in every practical way. One technical note: JPG does not support transparency, so transparent areas are filled with white during conversion; classic BMPs rarely use transparency, but files that do still convert cleanly. Your originals stay untouched on your device either way.