On my laptop, QOI encodes a test corpus at about 78 MP/s to a density of about 8.0 bits per pixel. Fast png encoding with fpng is 71 MP/s and reaches about 7.8 bpp.
Fast lossless jxl encoding can be done at 162 MP/s (single-core, faster with more cores) and reaches about 6.8 bpp. It can also be decoded in parallel, unlike QOI and PNG. It doesn't have a single-page spec though :)
On my laptop, QOI encodes a test corpus at about 78 MP/s to a density of about 8.0 bits per pixel. Fast png encoding with fpng is 71 MP/s and reaches about 7.8 bpp. Fast lossless jxl encoding can be done at 162 MP/s (single-core, faster with more cores) and reaches about 6.8 bpp. It can also be decoded in parallel, unlike QOI and PNG. It doesn't have a single-page spec though :)