BMP to JPG

How it works

BMP is Windows' native bitmap format, and most BMP files store every pixel completely uncompressed — practical in the 1990s, wasteful today. This tool converts BMP images to JPG directly inside your browser tab, using the mozjpeg encoder for a smaller, cleaner result than a browser's built-in JPEG encoder.

When you drop a file, Moyang reads its first bytes to confirm it's really a BMP, then hands the bytes to a background Web Worker for decoding and re-encoding. Older BMP variants can carry a basic transparency channel, so any transparent pixels are composited onto the background color you choose above — white by default — before mozjpeg encodes the result. Your original file is never modified, and nothing ever leaves your device.

Because everything runs locally, there's no 10-conversions-a-day limit, no 100MB cap, and no processing queue — the kind of restrictions server-based converters impose to control their hosting bill. Convert one file or fifty; once a batch is done, download every result at once as a single ZIP.

Limitations

JPEG is a lossy, quality-adjustable format, so encoding always discards some detail — usually an easy trade for BMP's typically enormous, fully uncompressed file size. Images over 100 megapixels aren't converted — decoding runs entirely in your browser's memory, and a file that large risks crashing the tab before it even gets to JPEG encoding.

FAQ

Is this BMP to JPG converter really free?

Yes — completely free, with no file size limits, no daily quota, and no account required. All conversion happens in your browser, so there's no server cost to recoup.

Why is the JPG so much smaller than the original BMP?

Most BMP files store every pixel completely uncompressed — a screenshot that's a few hundred kilobytes as JPG can easily be tens of megabytes as BMP. JPEG's lossy compression is the whole reason the file shrinks so dramatically.

Where do BMP files even come from?

BMP is Windows' native bitmap format — screenshots, some scanner and Windows Paint exports, and older Windows software still produce it by default. Converting to JPG makes these files practical to email, upload, or store in bulk.

Is there a file size or batch limit?

No batch limit — convert as many files as you like. Individual images are capped at 100 megapixels, which covers even the highest-resolution phone cameras; this keeps conversion from overwhelming your browser on unusually large or corrupted files.