To compress files for a system like Dropbox we would recommend a) check if the file can compress with https://github.com/dropbox/lepton https://github.com/dropb

To compress files for a system like Dropbox we would recommend a) check if the file can compress with https://github.com/dropbox/lepton https://github.com/dropbox/lepton . Lepton has some new flags that can help it compress a wider range of files, so it's not just limited to pure JPEG files any longer. b) then compress it with zlib -6 to get an idea of how compressible the data is. c) if the data compresses by at least a percent with zlib, it's likely to do significantly better with more advanced compression like DivANS. About 1/3 of files in Dropbox fall into that >1% category but aren't compatible with Lepton. For those compressible files, DivANS gets 12.08% savings over zlib with the settings we chose in the blog post. Brotli, in contrast, gets 9.64% savings over zlib on that same data.