What is 7 Zip

7-Zip is a file archiver with a high compression ratio.
The main features of 7-Zip are:
  • High compression ratio in new 7z format with LZMA compression
  • Supported packing / unpacking formats: 7z, ZIP, GZIP, BZIP2 and TAR
  • Supported formats for unpacking only: ARJ, CAB, CHM, CPIO, DEB, DMG, HFS, ISO, LZH, LZMA, MSI, NSIS, RAR, RPM, UDF, WIM, XAR and Z.
  • Compression ratio for ZIP and GZIP formats: 2-10 % better than the ratio provided by PKZip and WinZip
  • Strong AES-256 encryption in 7z and ZIP formats
  • Self-extracting capability for 7z format
  • Integration with Windows Shell
  • Powerful File Manager
  • Powerful command line version
  • Plugin for FAR Manager
  • Localizations for 74 languages

Compression ratio

We compared 7-Zip with some of the leading archivers.
FILE SETS: Mozilla Firefox 1.0.7 for Windows and Google Earth 3.0.0616 for Windows after full installation.
ArchiverMozilla FirefoxGoogle Earth
161 files
15,684,168 bytes
115 files
23,530,652 bytes
Compressed sizeRatioCompressed sizeRatio
7-Zip 4.23 (7z format)4621135100%6109183100%
WinRAR 3.505021556109%6824892112%
CABARC 5.15131393111%7434325122%
WinZip 10.0 beta (maximum-PPMd)5277118114%8200708134%
7-Zip 4.23 (zip format)6222627135%8909446146%
WinZip 10.0 beta (maximum-portable)6448666140%9153898150%
Compression ratio results are very dependent upon the data used for the tests. Usually, 7-Zip compresses to 7z format 30-70% better than to zip format. And 7-Zip compresses to zip format 2-10% better than most of other zip compatible programs.