Launched back in 1999, the open source 7-Zip joins WinZip and WinRAR in a battle royale between file archivers. Like its two rivals, it compresses data into a proprietary format - a compact 7z container that uses advanced LZMA and LZMA2 compression algorithms.
How LZMA and LZMA2 function isn’t as important as knowing what benefits they bring to 7-Zip. Specifically, the 7z archive format benefits from a high compression ratio and supports 256-bit AES encryption. This software squashes your files into tiny packages and protects them with a bank-level security lock-down. It also enables you to create self-extracting 7z archives.
Usefully, 7-Zip doesn’t just create archives in its native 7z format. It can also squash and spit out XZ, BZIP2, GZIP, TAR, ZIP and WIM archives.
The list of compression formats that it can unpack is far longer and includes the following file types: ARJ, CAB, CHM, CPIO, CramFS, DEB, DMG, FAT, HFS, ISO, LZH, LZMA, MBR, MSI, NSIS, NTFS, RAR, RPM, SquashFS, UDF, VHD, WIM, XAR and Z. Note the RAR support here. That’s handy.
7-Zip argues that it’s a better Zip archive creator than the original WinZip, claiming “a compression ratio [for ZIP and GZIP formats] that is 2-10 % better than the ratio provided by PKZip and WinZip.”
It also suggests that the native 7z compression in 7-Zip is typically between 30% and 70% more efficient than the Zip format. Although take this with a pinch of salt - the level of compression that you get depends on the type of file being compressed.
That said, 7-Zip is simple to install and easy to use. It integrates itself in the Windows context menu and acts as a plug-in for the FAR manager. In addition to the graphical user interface, 7-Zip includes a powerful command line version.
Verdict: The open source software 7-Zip impresses with its superb compression, reliability and compatibility with other archive formats. The program champions the 7z format, which seems to be significantly superior to other packaging formats when it comes to compression rates.
Note: This freeware app is supports more than 60 languages. All the updates for version 9.0 you can be found in the release notes on the homepage of the manufacturer. Highlights are the support for LZMA2 and NTFS-, FAT-, VHD- and MBR-archives.