Free BMP (.bmp) to WebP (.webp) converter — batch conversion with quality control, entirely in your browser. No upload, no signup.
PNG · JPG · WebP · BMP · GIF · SVG · AVIF
BMP is the uncompressed Windows bitmap format: raw pixels with a header. Files are enormous but trivially simple, which is why BMP still appears in legacy Windows software, embedded systems and scientific tooling. There is almost never a reason to keep an image in BMP.
WebP is Google’s modern web image format, supported by every current browser. It compresses roughly 25–35% smaller than JPEG at equal visual quality, supports transparency like PNG, and does both lossy and lossless modes — the pragmatic default for images shipped on websites today.
Yes — free, unlimited and without watermarks. Conversion runs on your own machine, so there are no server costs behind it.
No. Your browser decodes the BMP file and re-encodes it as WebP locally using the Canvas API. Nothing is transmitted anywhere.
The default 90% is visually indistinguishable from the source for almost all images. Around 80% is a good target for photographs on a web page. Below about 70% you start to see artefacts on flat areas and around sharp edges, and each re-encode compounds them.
Yes — drop any number of files and convert the whole batch in one click. A single result downloads as a file; a batch arrives as a ZIP, and each row shows the new dimensions and the size change.
This converter writes lossy WebP using the quality setting you choose. It keeps visible pixels and optional transparency, but it does not copy source metadata or animation.