Pragzip actually decompress in parallel and also access at random. I did a Show HN here: https://news.ycombinator.com/item?id=32366959 https://news.ycombinator.

Pragzip actually decompress in parallel and also access at random. I did a Show HN here: https://news.ycombinator.com/item?id=32366959 https://news.ycombinator.com/item?id=32366959 indexed_gzip https://github.com/pauldmccarthy/indexed_gzip https://github.com/pauldmccarthy/indexed_gzip can also do random access but is not parallel. Both have to do a linear scan first though. The implementations however can do the linear scan on-demand, i.e., they scan only as far as needed. bzip2 works very well with this approach. xz only works with this approach when compressed with multiple blocks. Similar is true for zstd. For zstd, there also exists a seekable variant, which stores the block index at the end as metadata to avoid the linear scan. indexed_zstd offers random access to those files https://github.com/martinellimarco/indexed_zstd https://github.com/martinellimarco/indexed_zstd I wrote pragzip and also combined all of the other random access compression backends in ratarmount to offer random access to TAR files that is magnitudes faster than archivemount: https://github.com/mxmlnkn/ratarmount https://github.com/mxmlnkn/ratarmount