ZIP Format

Compression ratio results are very dependent upon the data used for the tests. We compared 7-Zip with some of the leading commercial archivers: PKZIP 2.04g, WinZip 7.0.

FILE SET: The Canterbury Corpus (11 files totaling 2,810,784 bytes, popular file set used to compression rates).

Archiver Compressed size Ratio
7-Zip (zip format) 676284 100%
PKZIP 2.04g -ex 726047 107%
WinZip 7.0 (Max) 731499 108%

7z Format

7z is the new archive format, providing a high compression ratio.

FILE SET: The GIMP 1.2.4 for Windows after full installation (127 subfolders, 1304 files totaling 27,128,826 bytes). The GIMP is the GNU Image Manipulation Program. It can be downloaded from

Archiver Compressed size Ratio
7-Zip (7z format) 5445402 100%
WinRAR 3.10 6004155 110%
WinAce 2.3 6242424 115%
CABARC 1.0 6455327 119%
7-Zip (zip format) 9461621 174%
PKZIP 2.50 9842800 181%

GZIP Format

7-Zip provides the best compression ratio for GZIP format. The compression ratio is equal to its compression ratio for ZIP format (above).