Freeing space on your Mac OS X startup disk

Freeing space on your Mac OS X startup disk

The following tips will help you to free some space on your Mac OS X startup disk. 

Part I.  Determining available space on your startup disk

To check how much free space is available on your startup disk:

  1. In Finder, ensure you have selected the "Hard Disks" in the Finder Preferences


  2. Select your startup disk's icon from the Finder window.  (e.g. 109USMSF14)

  3. Press the Command-I keyboard combination.

  4. The Get Info window for your startup disk will open. In the General pane, the Capacity, Available (free space), and space Used on your startup disk will be displayed, as seen in the following screen shot:

    Ensure you have at least 10% “Available” based on your capacity.  For example, if your have 120 GB hard drive, make sure you have at least 12 GB of free space.  

Part II. Finding What Takes Up Space


Generally, the largest contributors, to a lack of local disk space are applications, games, presentations (like powerpoint), photos, and music.

To get a general idea of which files are taking up the majority of your space:

  1. Click the apple in the upper left corner of your screen and select “About This Mac” from the dropdown menu.

  1. Click on the “Storage” tab to view a breakdown of how your storage is being allocated.

In the image above you can see “Apps” take up the largest portion of my computer’s local storage.

The category “Other” takes up the second largest amount of space. “Other” can be many different types of files including PDF, PSD (Photoshop files are big), .zip, screensavers, extensions, cloud files (Dropbox or Drive folders synced to a local folder), and more.

Many of these files can be easily accessed by going into the Finder. The left panel shows large folders where types of documents are stored.

Clearing your downloads folder of items you are no longer using can be a good way to clear space. The video highlighted in green will clear the most space. There are other files I have no more use for, but they are so small there will be little space cleared by deleting them.

Be sure you know what you are deleting before doing so.


Accessing the computer’s Library can easily be accomplished by using the “Go” dropdown menu on your desktop and pressing and holding the Alt/Option key to reveal the Library.


Part III. Simple ways to free space

You can employ any of the following tips to increase the free space available on your Mac OS X startup disk without altering your hardware.

Step 1: Empty the Trash

As obvious as it may sound, some folks regularly Trash files but neglect to periodically empty the Trash. In Finder, select Finder > Empty Trash.

Note:  Some applications, such as iPhoto®, iMovie®, and Mail, have their own Trash, spearate from the Trash seen in the Dock. Emptying the application’s Trash may delete its contents immediately or move its contents to your personal Trash, which you can then empty as noted above.


Step 2: Upload Files to Google Drive, then delete the local files.

  1. Sign into your Google account and navigate to your Google Drive folder.

  2. Drag files from your computer’s local storage into the Google Drive folder.

  1. Once you have confirmed your files have been uploaded to Drive completely, delete them from your computer’s local storage.

  2. Empty the Trash to permanently delete the files as described in Step 1. 

Step 3: Backup the files to an external drive or SD card, then trash the local files.




This extract from a chapter of our book Troubleshooting Mac® OS X describes several ways to free-up space on your Mac OS X startup disk, also known as your Mac OS X boot volume. 

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