There's more low-hanging fruit before picking a different compressor, too. For instance, sorting the data: $ zcat openftp4_all_20160918.gz | sort | gzip -9

There's more low-hanging fruit before picking a different compressor, too. For instance, sorting the data: $ zcat openftp4_all_20160918.gz | sort | gzip -9 > sorted.gz $ ls -lha *.gz -rw-r--r--+ 1 mappu mappu 3.9M Sep 18 18:17 openftp4_all_20160918.gz -rw-r--r--+ 1 mappu mappu 2.2M Sep 18 18:19 sorted.gz `zpaq` should out-compress xz on the unsorted file, too, but i haven't tried it.