How to Zip and Unzip Files and Folders on a Mac

Question:

I've always used a third-party app on my PC to zip files before I send them off to friends or upload them to my website. How do I do this on my new Mac?

Answer:

There are a number of free and low-cost third-party compression apps available for the Mac. The Mac OS also comes with its own built-in compression system that can zip and unzip files. This built-in system is fairly basic, which is why so many third-party apps are also available.

A quick look at the Mac App Store revealed over 50 apps for zipping and unzipping files.

In this FAQ, we'll show you how to compress and decompress files and folders using the zipping tool built into the Mac. It's a basic tool, but it gets the job done.

OS X Compression App

The app is called Archive Utility, and includes a number of options that you can modify. But don't bother to look for it in the Applications folder; it's not there. Apple hides the app because it's considered a core service of the OS. Apple and app developers can use core services to enhance an application's capabilities. For example, Mac Mail uses the service to compress and decompress attachments; Safari uses it to decompress files you download.

I mentioned that the Archive Utility had a number of settings that could be modified and you can try making changes some time later, right now it is a better idea to get use to the utility as configured in its default state, you can always try new settings later on.

The Archive Utility may be hidden away, but that doesn't mean you can't access its services. Apple makes zipping and unzipping files and folders extremely easy by allowing the Finder to access and use the Archive Utility app.

Zipping a File or Folder

Open a Finder window and navigate to the file or folder you wish to zip up.

Control-click (or right-click if you have a mouse with that capability) the item and select Compress from the pop-up menu. The name of the item you select will appear after the word Compress, so the actual menu item will read Compress "item name."

The Archive Utility will zip the selected file; a progress bar will display while the compression is occurring.

The original file or folder will be left intact. You'll find the compressed version in the same folder as the original (or on the desktop, if that's where the file or folder is located), with .zip appended to its name.

Zipping Multiple Files

Compressing multiple files and folders works just about the same as compressing a single item. The only real differences are in the names of the items that appear in the pop-up menu, and the name of the zip file that is created.

Open the folder that contains the files or folders you want to zip up.
Select the items you want to include in the zip file. You can command-click to select non-adjacent items.
When you've selected all of the items you want to include in the zip file, right-click on any one of the items and select Compress from the pop-up menu. This time, the word Compress will be followed by the number of items you have selected, such as Compress 5 Items. Once again, a progress bar will display.

When the compression is finished, the items will be stored in a file called Archive.zip, which will be located in the same folder as the original items.

If you already have an item in that folder named Archive.zip, a number will be appended to the new archive's name. For instance, you could have Archive.zip, Archive 2.zip, Archive 3.zip, etc.

One curious aspect of the numbering system is that if you delete the Archive.zip files at a later date, and then compress multiple files in the same folder, the new Archive.zip file will have the next number in the sequence appended to it; it won't start over.

For example, if you compress three groups of multiple items in a folder, you'll end up with files called Archive.zip, Archive 2.zip, and Archive 3.zip. If you delete the zip files from the folder, and then zip another group of items, the new file will be called Archive 4.zip, even though Archive.zip, Archive 2.zip, and Archive 3.zip no longer exist (or at least, not in that folder).

Unzipping a File

Unzipping a file or folder couldn't be easier. Double-click the zip file and the file or folder will be decompressed into the same folder the compressed file is in.

If the item you are decompressing contains a single file, the new decompressed item will have the same name as the original file.

If a file with the same name is already present in the current folder, the decompressed file will have a number appended to its name.

For Files That Contains Multiple Items

When a zip file contains multiple items, the unzipped files will be stored in a folder that has the same name as the zip file. For example, if you unzip a file called Archive.zip, the files will be placed in a folder called Archive. This folder will be placed in the same folder as the Archive.zip file. If the folder already contains a folder called Archive, a number will be appended to the new folder, such as Archive 2.