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Last updated: March 6, 2024
Clean Mac System Data

How to Delete System Data on a Mac: Comprehensive Guide

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Is your Mac displaying the low storage space alert? Check your Mac’s storage settings, and you’ll notice a mysterious bunch of files, labeled “System Data,” taking up quite a bit of storage space. Fortunately, there is a way to clear up some of the System Data on your Mac and reclaim your precious storage space. The sections below outline what System Data is, and the most efficient methods to clean it up.

Step 1: Identify What Takes Up The Most Space

Before you clear the System Data on your Mac, you need to know what’s actually hogging up your Mac’s storage space, because it isn’t always clear.

Moving your enviable film and music collection to another storage device may not free up as much space as you expected. Because it’s often System Data—hidden files, app cache, browser cache, old backups, and temporary files—that takes up a surprising amount of storage space.

There are two methods to identify what’s taking up space on your Mac—using the storage information screen in macOS, and using third-party storage space analyzers. Your Mac’s built-in storage information screen gets the job done if you want a basic overview of what’s taking up space on your Mac. For more advanced analysis, I suggest using a third-party storage analyzer.

Here’s how to find out what’s taking up space on your Mac:

Method 1: Check Your Mac’s Storage Information

The built-in storage space analyzer in macOS neatly displays the file categories taking up storage space on your device. It also contains suggestions on how you can free up storage space on your Mac.

Accessing your Mac’s storage information is simple:

  1. Click on the Apple logo on the top-left corner of your screen, and select About This Mac.A Finder menu on a Mac with an arrow pointing to the "About This Mac" option.
  2. Click on More Info.The "About This Mac" overview window displaying the MacBook Air model with an M2 chip, 8GB of memory, and other details, with a "More Info..." button highlighted.
  3. Click on Storage Settings under Storage.The detailed "About" section of the Mac settings, showing the macOS version, chip details, memory, and a highlighted "Storage Settings..." button.
  4. You can now see what’s taking up storage space on your device. A dark gray bar denotes the space taken up by System Data. You can also scroll down towards the bottom of the screen to see exactly how much space System Data is occupying.The storage management window on a Mac, displaying the used and available space on Macintosh HD and an arrow pointing to the "System Data" category within the storage breakdown.
  5. (Optional) Click the i icon next to a category to view and delete individual files in that specific category. This option is unavailable for the System Data, and macOS categories.The System Settings window showing the "Storage" section with various categories, and the "Applications" category is highlighted, indicating its size on the disk.

Method 2: Use Third-Party Storage Analysis Tools

If, like me, you found Mac’s storage information screen lacking in detail, you can use third-party storage analyzers for a more in-depth analysis of what’s taking up space on your Mac.

I didn’t wish to spend money on a fancy disk analysis and cleaning tool, so I ended up using OmniDiskSweeper to find out what files were taking up the most space on my M2 MacBook Air, running macOS Sonoma. However, you can take your pick from these third-party disk space analyzers.

Here’s how I used OmniDiskSweeper to analyze storage space on my Mac:

  1. Download and install OmniDiskSweeper.
  2. Open OmniDiskSweeper, and provide it with the necessary permissions to access your storage.
  3. Select your storage drive, usually “Macintosh HD,” and click the Sweep button.OmniDiskSweeper interface showing Macintosh HD selected with information on free space, used space, and total capacity, and a button at the bottom labeled "Sweep 'Macintosh HD' Drive..."
  4. OmniDiskSweeper will list the directories on your disk (even the hidden ones), and the amount of space they’re taking. Be cautious, as many of these directories contain critical system files that shouldn’t be deleted or changed.Detailed view in OmniDiskSweeper displaying various folders and files on Macintosh HD, including their sizes, with the "" highlighted and its size of 966.1 MB displayed, indicating it's a significant item taking up space.

If you see media files, documents, and unused apps taking up excessive storage space on your Mac, move them to another device, or delete them.

Step 2: How to Delete System Data on Mac

Apple doesn’t explain clearly what “System Data,” contains, and why it’s occupying substantial storage space on your Mac.

So, I did some research, and here’s what I found.

System Data mostly comprises app-specific cache files, log files, temporary files, VM files, fonts, plug-ins, Time Machine backups, and iOS backups. Unless you actively clear app caches, orphaned files, and temporary files—System Data will increase in size as you use your device, install new apps, etc.

Here’s an excellent resource on what System Data contains.

My MacBook Air’s System Data is relatively small in size because I bought it less than a year ago, and I don’t use it all that much. However, if your device is old, used heavily, and you’ve never reset it, the macOS System Data is likely huge.

Here’s what I did to reduce the size of System Data on my Mac:

Method 1: Remove Old Backups

Time Machine is macOS’ native backup and restore feature. Besides backing up your data to the separate Time Machine drive, Mac also creates local snapshots of your data. You can delete these local snapshots/backups to reduce System Data size on your Mac. In addition to Time Machine backups, there may be older, unrequired iOS backups taking up space on your Mac.

Here’s how to delete these old backups to clean up some of the System Data on your Mac:

Part A: Delete Old Time Machine Backups

  1. Open Spotlight Search (Command + Space), type in “Terminal” and launch the Terminal app. You can also find it in Finder > Go > Utilities.
  2. Type in tmutil listlocalsnapshotdates and press Enter. You’ll see a list of all local Time Machine snapshots. Each snapshot will be named in this format: YYYY-MM-DD, followed by a numerical string. On my MacBook, there was just one local Time Machine snapshot, titled 2023-11-30-123142.Terminal window on a Mac displaying the output of the 'tmutil listlocalsnapshots' command with an arrow pointing to a snapshot date for the disk.
  3. Type tmutil deletelocalsnapshots XXXXX, where XXXXX denotes the name of the local snapshot you wish to delete. Press Enter. In my case, the command was tmutil deletelocalsnapshots 2023-11-30-123142.Terminal window on a Mac showing the command 'tmutil deletelocalsnapshots' being used to delete a specific local snapshot, with an arrow indicating the confirmation of the deleted snapshot.
  4. Repeat these steps for other local snapshots you want to delete.

Part B: Delete Old iOS Backups

If there are any iOS backups on your Mac, you can locate and manage them in Finder:

  1. Connect your iPhone to your Mac
  2. Open Finder.
  3. In the left navigation bar, click on your iPhone/iPad under Locations.Finder window on a Mac displaying "Manuviraj’s iPhone" in the Locations sidebar, with the device's general settings showing capacity, available storage, battery level, and software version in the main pane.
  4. Click on Manage Backups.The Finder window on a Mac, with the device summary for "Manuviraj’s iPhone" shown, and the "Manage Backups..." option highlighted, indicating where the user can manage their iPhone backups.
  5. Select the backup you wish to delete and click Delete Backup.A pop-up window showing the list of device backups, with "Manuviraj's iPhone" selected and a "Delete Backup" button below.
  6. Click Delete in the confirmation prompt.
Don’t see any backups after you click Manage Backups? It’s likely your iOS device is backed up to iCloud, and there aren’t any iOS backups stored on your Mac.

iOS backups can also be located in ~Library/Application Support/MobileSync/Backups, if you don’t wish to connect your iPhone to the Mac.

Method 2: Delete Temporary Files

Third-party apps, and even macOS, create temporary files over time. These temporary files may include browser cookies, logs, document snapshots, and more.

An easy way to delete temporary files is to restart your Mac. No, this doesn’t mean simply closing the lid of your MacBook and re-opening it. You need to Shut Down your Mac, and power it on again. This forces active apps and system processes to quit and start again. Please save any unsaved projects before rebooting your Mac.

Here’s how to delete temporary files and consequently get rid of some System Data on your Mac:

  1. Click the Apple icon on the top-left corner of your Mac’s screen.
  2. Click on Shut Down.A Finder menu on a Mac with an arrow pointing to the "Shut Down..." option.
  3. Power On your Mac again.

Method 3: Clear Out System Data Caches on Your Mac

The ~/Library folder usually contributes most to large System Data on your Mac. It’s because the folder contains app-specific caches, log files, screen recordings, and more. Tread carefully when cleaning out files from this folder, as some of them could be important for apps to work properly.

Bonus: Before proceeding further, enable the Calculate all sizes feature in macOS to know exactly how much space a folder is taking up—it’ll make your life much easier. To enable it, open Finder, click View > Show view options, and tick the Calculate all sizes option.

Follow this guide to know how to access, and what to delete from the ~/Library folder on macOS:

  1. Open Finder, and click on Go > Go To Folder.
  2. Type in ~/Library and press Enter.A Finder window on a Mac displaying a Go To Folder dialog box with the path "~/Library" entered, leading to the user's Library folder.
  3. Open the Caches folder.Finder window on a Mac showing the contents of the Library folder, with an arrow pointing to the "Caches" folder.
  4. Switch to List View to clearly see how much space is taken up by each cache folder.
  5. Find and open the app-specific folder you wish to delete the cache for, right-click all the folders in it, and click Move to Bin. In my case, I cleared the cache for Apple TV—-I opened the com.Apple.TV folder, and cleared its contents.Context menu in Finder on a Mac with the "Move to Bin" option highlighted for an item within the "" folder.

Additional pointers regarding app-caches:

  • Often, uninstalled apps don’t remove their cache. Look for these orphaned cache folders when clearing out the ~/Library/Caches.
  • Clearing out caches is usually a temporary measure, as most apps recreate the cache when you begin using them again.
  • If there are no missing features, I recommend using web-based versions of apps. As an example, the Notion app on my Mac created a 1.2 GB cache, prompting me to use the web version of it because it is just as good as the native app. Of course, this tip is situation-specific.

Besides the Cache folder, there are some other folders you can safely clean up to reduce System Data size on your Mac:

  • ~/Library/Containers/
  • ~/Library/Logs
  • ~/Library/Screen Recordings (only if you haven’t recorded anything you need).

Method 4: Check Your Downloads Folder

The Downloads folder can become a huge data hog, really quickly. I had hundreds of obsolete documents, installers, videos, and other files lying around in my Downloads folder. Deleting these old Downloads freed up a lot of space on my Mac.

While this doesn’t strictly fall into the category of “System Data,” clearing out the Downloads folder is an excellent way to free up storage space on your Mac.

Here’s how I did it:

  1. Open Finder and click on Downloads in the left navigation bar.Finder window on a Mac with the Downloads folder selected in the sidebar, showing various files and folders in the detail pane.
  2. Switch to List View for more details about each file, and folder.Finder window on a Mac displaying the Downloads folder with various files listed, and the "List View" display option highlighted at the top of the window.
  3. Click on the Size sort option and ensure it’s in descending order—so you see larger files first.Finder window on a Mac displaying the Downloads folder with various files listed, and the "Size" column header highlighted, indicating the sorting of files by size.
  4. Hold down the Command key and select the files you wish to delete. Then, right-click and choose Move to Bin.Context menu in Finder on a Mac with the "Move to Bin" option highlighted, indicating the action to delete a file.

Method 5: Empty the Trash Bin

By default, macOS doesn’t empty the Trash/Bin automatically. All deleted files remain there until you restore them, or empty the Bin. Naturally, the Bin may end up taking up GBs of storage space if you don’t clear it out frequently.

Again, clearing out the Trash Bin won’t reduce the size of “System Data,” but it’ll help you reclaim a lot of storage space.

Here’s how to clean up some of your Mac’s System Data by emptying the Bin:

  1. Click on the trashcan icon on the Dock to open the Bin.
  2. Right-click anywhere in the Bin, and choose Empty Bin.Finder window on a Mac showing the Bin with various files, and the context menu open for an image file with the "Empty Bin" option highlighted.

Step 3: Optimize Your System Storage

By following a few simple tips, you can prevent System Data from hogging up space on your Mac’s storage disk.

Some of these tips are:

  • Whenever you uninstall an app, double-check to see if its cache still exists in the ~/Library/Cache directory. If it does, delete the app’s cache.
  • After installing a third-party app, delete the installer, or move it to an external storage drive.
  • I recommend periodically cleaning the ~/Library/Logs folder. Over time, unnecessary log files can start occupying a lot of storage space.

In addition to these tips, macOS’ Storage Information screen recommends and lets you enable some storage saving options. Here’s how:

  1. Click on the Apple logo in the top-left corner of the screen and click About This Mac.About This Mac option.
  2. Click on More Info.More Info option in the About This Mac popup.
  3. Click on Storage Settings under Storage.Storage Settings button.
  4. Enable the options under Recommendations according to your preferences. I recommend enabling the Empty Bin automatically option. If you have enough iCloud storage, enable the Store in iCloud option as well.macOS Storage Recommendations.


On macOS, System Data consists of app caches, important system files, temporary files, logs, backups, and more. It’s used to categorize files that otherwise don’t fall into generic baskets like media, documents, applications, etc. Mac doesn’t let you easily access, or modify these files. You can find the amount of space System Data is occupying by going to Settings > General > Storage.

If macOS’ System Data is huge, it’s usually because of these reasons:

  • There are numerous applications installed on your Mac. These apps create caches, that are stored in the ~/Library folder, which is a part of System Data.
  • Too many old Time Machine, and iOS backups stored on your Mac.
  • Orphaned app data from uninstalled apps.
  • Files stored in the Bin.
Most files that contribute to System Data, are located in the ~/Library folder. This folder is usually hidden. To access it—open Finder, then click Go > Go To Folder, type ~/Library, and press Enter.


System Data can occupy precious storage space you need for other files and media. Before cleaning it up, analyze what folders and file types are taking up the most space on your drive. You can use Mac’s storage settings window, or third-party storage analyzers to do this.

To remove some of your Mac’s System Data, do the following—delete any old backups and temporary files, clean up app caches from the ~/Library folder, wipe out unneeded downloads, and empty the Bin. A good Mac cleaning software can make the job easier.

Once you’ve done that, it’s a good idea to enable macOS’ storage recommendations in the Storage Settings screen. This will help you manage the System Data on your Mac more efficiently.

Manuviraj is a professional writer with a keen interest in data recovery, and over 4 years of writing experience under his belt. Using his articles, he hopes to educate readers on how to keep their data secure, and the nuances of data recovery. When he’s not reading or writing about data recovery, Manuviraj likes to spend his time reading fiction, riding his motorcycle (or tinkering with it), and listening to music.
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