Convert BMP to WebP

No — that is the whole reason I built this. The conversion runs in your browser using WebAssembly, so your files never leave your device; there is no server in the loop at all. It also means the tool keeps working offline once the page has loaded, and there is no file size limit beyond your device’s memory.

WebP handles both kinds of content well: photos compress like JPG (slightly better), and graphics compress like PNG (usually better), all in one format every current browser renders. If the destination is a website, WebP saves you choosing per image.

Photos: typically 96–99% smaller at quality 82. Flat-color graphics and screenshots: 90–98%, since BMP stores them raw. The per-file readout shows your exact numbers — BMP conversions produce the most dramatic percentages on this site.

If they are one-of-a-kind originals (scans of family photos, source art), keep a lossless copy — either the BMP or a much smaller PNG of it. WebP at quality 82 is for publishing; a lossless master is for archiving. Storage is cheap; regret is not.

It is the opposite — the bigger the gap between two formats, the more the jump pays. BMP spends zero effort on compression; WebP spends three decades’ worth, so photos land 96–99% smaller and graphics 90–98%. The only genuine question is destination: WebP assumes a browser on the other end. If the file must open in old desktop software, the modern format will be what fails, not the conversion.

Compatibility with the past. The environments that still produce BMPs — legacy Windows tools, scanner utilities, industrial software — are exactly the ones that cannot open WebP. If the file loops back into that world, use BMP to PNG instead: still 50–90% smaller, and readable by everything made since the 1990s. Choose WebP only when the destination is the web.