lz4 (compression algorithm) LZ4 is lossless compression algorithm, providing compression speed at 400 MB/s per core (0.16 Bytes/cycle). It also features an extremely fast decoder, with speed in multiple GB/s per core (0.71 Bytes/cycle). A high compression derivative, called LZ4_HC, is also provided. It trades CPU time for compression ratio. This build includes liblz4 and the command-line lz4 tools.