Since macOS is based on Unix there are a number of ways to compress files and folders within the filing system using Unix based application code, below are a few options using the Terminal or command line interface (cli). The default command line application interface in macOS is the Terminal and is stored in /Applications/Utilities.

File and folder compression saves on file size and ensures the contents are captured and delivered or stored as one monolithic file. A compressed file which contains files and folders is generally referred to as an archive. Here are some built in compression applications you can use including zip, tar, gz, bz2, gz and dmg.

ZIP – Cross Platform

First up is ZIP one of the most commonly used compression techniques used across all platforms

To compress

zip -r archive_name.zip folder_to_compress

To extract

unzip archive_name.zip

If you want to make a zip without those invisible Mac resource files such as “_MACOSX” or “._Filename” and .ds store files, use the “-X” option in the command so:

zip -r -X archive_name.zip folder_to_compress

TAR.GZ – Cross Platform

Second up is TAR, an old favourite on Unix/Linux – you add the GZ for the compression – compresses tighter than zip

To compress

tar -zcvf archive_name.tar.gz folder_to_compress

To extract

tar -zxvf archive_name.tar.gz

TAR.BZ2 – Cross Platform

A variation on TAR GZ but with better compression than both tar.gz and zip.

To compress

tar -jcvf archive_name.tar.bz2 folder_to_compress

To extract

tar -jxvf archive_name.tar.bz2

GZ

Without the tar

To extract

gunzip archivename.gz

DMG – macOS Only

This one is macOSnative only – for a GUI interface use /Applications/Utilities/Disk Utility – for command line use:

To create

hdiutil create -format UDZO -srcfolder folder_to_compress archive_name.dmg

To mount

hdiutil attach archive_name.dmg

To view

ls -lah /Volumes/archive_name/

To Eject

hdiutil eject /Volumes/archive_name/

You can also use a number of different formats for creating a .dmg

• UDZO – Compressed image (default)
• UDRO – Read only image
• UDBZ – Better compressed image
• UDRW – Read/Write image
• UDTO – DVD disk image

That’s the low down, the more common compression packages available will typically be covered in one of the above.