A compressed file enables the file to use less storage space and to copy more quickly from one hard drive to another or over the Internet. A “7Z” compressed file, while common on PCs, is not recognised by the Mac’s OS X operating system and so will not open using the built-in commands that work with the more common “zip” compressed files. You must use a “7Z” compatible decompressing program in order to open a “7Z” type file on a Mac. There are a few of these types of programs available for Mac users, some of which are free to use on a trial basis and have a graphical interface rather than a command line menu. The procedure for decompressing a “7Z” type file using such a program is similar to that of other decompression programs that work on a Mac.
Download a “7Z” decompression program to the Mac’s desktop--for example, the trial version of the EZ7z decompression program (see the link in Resources). Double-click on the file once it has downloaded. Follow the menu commands to install the program onto the Mac’s hard drive.
Launch the “7Z” decompression program by double-clicking its icon inside of the “Applications” folder.
Drag the “7Z’ compressed file that is to be decompressed from the Mac’s hard drive onto the window that is on the left side of the “7Z” decompression program’s main screen.
Click the “Expand” button on the “7Z” decompression program. Wait for a pop-up window to appear on the desktop. Select “Desktop” from the “Locations” tab on the pop-up screen. Click the “Save” button at the bottom of the screen.
Quit the “7Z” decompression program once the pop-up window disappears. Archive or delete the “7Z” compressed file now that you have the decompressed version of it on the desktop.
You can discover a 7Z file by noting whether or not it has the .7z suffix following its name.