Using the Mac's Hidden Archive Utility to Control Compression

Tweak the settings to suit your needs

macOS' Finder uses the system's built-in Archive Utility to perform compression (archiving) and expansion of files in the background, without opening a window for the utility itself. It relies on several preconfigured defaults: For example, as installed, the Finder will always use the ZIP format and will always save archives in the same folder as the original. You can change these defaults for a bit more control over the archive format, what happens to the original files, and where expanded or compressed files are stored by using the Archive Utility directly.

The procedures and screenshots described here apply to macOS 10.15 (Catalina), but the they should be very similar in older versions of macOS and OS X.

Launching the Archive Utility Preferences

You'll find the Archive Utility at /System/Library/CoreServices/Applications (or at /System/Library/CoreServices in pre-Yosemite versions).

Search for "Archive Utility" in the Finder's search bar to find it quickly. Alternatively, open a Spotlight search by pressing command + spacebar.

Archive Utility opens without presenting a window; instead, there's just a set of menus along the top of the screen. To change the utility's defaults, open Archive Utility > Preferences.

macOS Archive Utility menu

Managing Archive Utility Preferences

The Preferences window is broken into two sections: one for expanding files, and the other, for compressing them.

macOS Archive Utility Preferences

Expansion Options

The options for expanding files are as follows:

Save expanded files: Select where you want to store expanded files on your Mac. The default location is the same folder that holds the archived file you're expanding. To change the destination for all file expansions, click the arrows to the right and navigate to the desired destination folder.

After expanding: This specifies what happens to the original file after it's expanded. The default action is to leave the archive file in its current location (leave archive alone), or you can choose from the drop-down menu to instead move the archive file to the trash, delete the archive, or move the archive file to specific folder. If you choose the last option, you'll be asked to navigate to the target folder. Remember, this folder will be used as the target location for all archived files that you expand. You can change your selections at any time, but it's usually simpler to select one location and stick to it.

Reveal expanded item(s) in Finder: When checked, this option causes the Finder to highlight the files you have expanded. This can be handy when the files in an archive have different names than what you were expecting.

Keep expanding if possible: This box is checked by default and tells the Archive Utility to keep expanding items it finds within the archive. This is helpful when an archive contains other archives.

Compression Options

Here are the configurable options for compression:

Save archive: This drop-down menu controls where the archive file is stored after the selected files are compressed. The default is to create the archive file in the same folder where the selected files are located. If desired, select the Into option to pick a destination folder for all created archives.

Archive format: The Archive Utility supports three compression formats.

  • Compressed archive, which is the same as a UNIX compression method called cpgz.
  • Regular archive, also known in the UNIX world as cpio. This method actually doesn't perform any compression; instead, it just creates a container file made up of all of the selected files.
  • ZIP is the final option, and the one most Mac users are familiar with. This is the standard ZIP format that has been used on Mac and Windows computers for years.

After archiving: Once you finish archiving files, you can leave the files alone, which is the default option; move the files to the trash; delete the files; or move the files to a folder of your choice.

Reveal archive in Finder: When checked, this box will cause the archive file to be highlighted in the current Finder window.

The options you've set will apply only when you manually open the Archive Utility to expand/compress files. Finder-based compression and expansion will always use the factory-default options, no matter how you set the preferences here.

Using the Archive Utility

Launch Archive Utility, if it's not already open. To compress files:

  1. Select File > Create Archive.

    macOS Archive Utility Create Archive
  2. A window will open that you can use to navigate to the folder that contains the items you wish to compress. Make your selection, and then click Archive.

 To expand an existing archive:

  1. Select File > Expand Archive.

  2. A window will open that you can use to navigate to the folder that contains the archive you wish to expand. Make your selection, and then click Expand.