How to Open 7Z Files on Mac
By Shea Laverty
While Windows users can access 7z files by using the format's native decompression utility 7-Zip, the program lacks an official Mac release. Apple aficionados need not despair, however: The 7z format can be opened by a bevy of compression apps on OS X, most of which are free. In addition to decompressing these files, these apps can also compress files on your Mac into a 7z file, as well as opening other archive formats.
All 7z files are file archives developed by 7-Zip and similar to other long-standing compressed archives like ZIP and RAR. They differ from these other formats mostly because of the algorithm used in file compression. Using this compression algorithm, large files like high-definition video can be dramatically reduced in size for easier sharing or long-term storage. Like other archive files, 7z files can also be encrypted with a password for additional security. The overall size of a 7z file depends primarily on the total amount of data contained with and the level of compression applied, although a 7z file will never be larger than the sum of its contents.
The Unarchiver is a decompression utility developed for OS X by Dag Agren. Available in 18 languages, the Unarchiver is a lightweight app that can opens quite a few formats including 7z, ZIP, RAR and TAR. The Unarchiver is intended purely as a decompression tool and as such cannot create new archives, making it a little less useful for anyone who needs to compress their own 7z files in addition to opening them. The Unarchiver requires OS X 10.6.0 or later to run properly.
Keka is a general-purpose compression utility developed by Jorge Garcia Armero. Like the Unarchiver, Keka can access and decompress 7z, ZIP, RAR and many other compressed archives. Unlike the Unarchiver, however, Keka also features the ability to compress your own archives using the 7z, ZIP, TAR, Gzip, Bzip2, DMG and ISO formats. Keka can also compress larger files into several pieces, making them easier to share or store. Keka is available for free from the Keka website, but has a very small cost when purchasing from the Mac App Store. Keka requires Mac OS X 10.6.0 or later to run properly.
Ez7z is a general-purpose compression utility originally developed by Leif Heflin. Ez7z is a somewhat more limited app, only capable of decompressing 7z, ZIP, RAR, Bzip2 and TAR files. It can also compress files into 7z, ZIP, Bzip2, GZ and TAR archives. Originally a paid app, this utility is now available for free because it's no longer actively developed or updated. As such, this app's support in OS X may diminish over time, making the other apps potentially stronger candidates in the long run. Ez7z requires OS X 10.5.0 or later to run properly.