BMP is uncompressed by design. Practically any other format is smaller, usually by 80–95%.
—
80
Resize
50
Encoder detail
6
fastzopfli
256
28
0 lossless51 tiny
The largest saving available.
50
Speed, audio and advanced
8
0 smallest13 fastest
128
96
Advanced
8
Nearly all of the saving comes from the images inside.
150
75
Advanced
50
aggressivegentle
Advanced
14
coarsefine
0 merges only exactly equal vertices. A small value also closes hairline cracks left by CAD exporters.
Geometry only — texture coordinates,
materials and vertex colours are not carried through. Decimating a
UV-mapped mesh correctly is a much harder problem, and mangling your
UVs quietly would be worse than leaving them alone.
12
6
Advanced
ZIP and 7z. 7z encrypts the file list too.
What actually shrinks BMP files
PNG is the lossless replacement — identical pixels, a fraction of the size.
If the image is a photograph and exactness doesn't matter, JPEG or WebP will be smaller still.
Decoding runs through our own Rust decoder in WebAssembly, since browsers won't read BMP natively.