How to clear System Data on Mac: 7 ways to free up space

Have you ever checked the Storage settings of your Mac? You may have noticed a colored bar segment named ‘System Data.’ Based on our experience, sometimes, it can be over 100 GB (e.g., if you use your Mac for software development or video editing). But what is it, why is Mac System Data large, and how do you clear it? We’ve got all the answers here. Keep on reading, and you’ll learn 7 ways to free up space on your Mac, starting with System Data. Let’s dive in!

What is System Data on Mac?

System Data in macOS once used to be Other storage. It includes all types of data that do not fall into other categories of storage: Applications, Documents, iCloud Drive, iOS files, Photos, etc., along with other system files and caches.

So, what does System Data include?

• Application leftovers: Files that remain in the system after you delete an app
• Temporary files & cache: Application caches, browser caches, system cache, etc.
• Browser plug-ins & extensions: Tools for customizing apps and web browsers
• Other files: VM files, fonts, macOS data, app support files, system log files, system application files

System Data is mainly stored in the Library folder.

Why does System Data take up so much space on Mac?

Apple says that the size of the category varies depending on the current state of your Mac. macOS clears caches and safe-to-delete log files once space is needed. It also removes temporary database files, macOS and app updates, Safari website data, and interrupted downloads.  

How to check System Data storage on Mac

Now that you know what System Data is, let’s find out how to check it. The steps are pretty straightforward: 

1. From the main Apple menu, go to System Settings.
2. Click General > Storage, and you’ll see what’s taking up space on your Mac. 
3. Check the colored graph — hover over the gray segment to see how much space System Data occupies. Alternatively, scroll down to the bottom of the window and find that System Data category.

Now, we’re going to show you what to do when Mac System Data grows too large.

Can you delete system data on Mac?

Yes, but make sure that you follow the steps below accurately. Also, always double-check everything before sending it to Trash.

How to clear System Data and free up space on Mac: 7 ways

With the help of the steps below, we reduced System Data from 115 GB to 48 GB. 

We tested these cleaning tips on two Macs: 

• MacBook Pro with Apple M5 Pro chip running macOS Golden Gate. The most effective ways in terms of freeing up storage were deleting system junk, cleaning up the Downloads folder, and optimizing storage. However, this Mac is not used for backing up other Apple devices and Time Machine snapshots are not enabled. 
• MacBook Air with Apple M4 chip running macOS Tahoe that is used for backups and has Time Machine snapshots enabled: removing iOS backups and Time Machine snapshots helped reclaim almost 30 GB of space. 

So, we suggest following all of the steps below one by one and seeing how much storage space you can free up.

1. Browse system folders

Believe it or not, one thing you can do is wait. When you first open Storage settings, macOS seems to allocate quite a lot to System Data that it then reallocates elsewhere. For example, some users have reported that after waiting for a few minutes, much of the storage labeled ‘System Data’ is moved to the iCloud label. So, if you wait, you might find that the System Data isn’t taking up disk space in the huge quantities that it seemed to be at first.

The other thing you can do is investigate what files are designated as ‘System Data.’ Files in your Mac’s Library folders that don’t belong to another storage category come under the ‘System Data’ heading. That is:

/Library

~/Library

Click the Go menu in Finder and select Go to Folder, then paste in each of the paths above in turn.

Go through the subfolders in each and press Command-I to Get Info and check how much data is in each. You’ll quickly discover where your precious storage has gone.

It’s likely that much of it is accounted for by cache files for apps like Photos and Safari. macOS caches as much data as it can to avoid having to re-download it, which boosts performance. And it’s smart enough to know that it must delete cache files when you run low on storage.

If you decide that you don’t want to leave it up to the operating system to free up storage, don’t just start trashing cache files or folders randomly, you might delete something you shouldn’t. So be careful and remove only individual files and never delete folders. Better still, follow other steps described below instead and return to this one only if they have not helped. 

2. Check for unnecessary files 

Much of the storage space used by the OS for system-related tasks is cleared when macOS deletes the files automatically, but sometimes, that doesn’t happen, which is why the System Data category can grow very large. It’s likely that the following are part of it:

• Log files
• App cache files
• Temporary files from past sessions

Not knowing what files are included in System Data storage makes finding them tricky. However, it’s far from impossible. Our favorite tool for clearing unnecessary system junk from Mac is CleanMyMac. It has lots of tools for clearing out junk files, but for our purposes, there’s one that really helps — Cleanup. This handy feature scans your Mac and identifies things like temporary files, translation files in apps, broken preferences files, and system cache files that are no longer needed. You can then remove them with one click. Or you can choose which ones you want to get rid of and remove just those. Get your free CleanMyMac trial.

Once you’ve downloaded and installed it, here’s how to find system junk and reclaim some space with the help of CleanMyMac:

1. Open CleanMyMac.
2. Choose Cleanup in the sidebar and click Scan.
3. Once it’s finished, click Clean in the System Junk tile to remove the system junk it found without reviewing it.
4. Or, if you want to know what will be removed first, click Review All Junk and go through the list of results.
5. Deselect the checkboxes next to any items you don’t want to delete and click Clean Up to remove the rest.

That removes system cache and log files, which Apple counts as System Data.

If you use Photoshop or another media editor, you’ll see the option to delete Document Versions — intermediate edits of your files. Also, you can remove unused language files, Xcode cache and other derived data, VM-related cache, Microsoft cache, and other similar stuff. 

And if you use AI tools, the Cleanup tool also has an AI Clutter category that lists caches, logs and temporary files of these AI tools, along with the models downloaded with Ollama and LM Studio. In other words, you have many options for freeing up space at your disposal. 

Why use CleanMyMac

• According to internal reports, on average, users find and remove over 5 GB of safe-to-delete junk files with the help of the Cleanup tool.
• Based on internal data, on average, the Cleanup scan/clean process takes up less than 2 minutes.
• 25+ tools to clean, maintain, and protect your MacBook

Try CleanMyMac for free — see the difference it can make for your Mac. 

3. Clear application logs and support files

Apps generate lots of files. They help improve your experience within the app, but when you remove the application, those leftover files may still be stored on your Mac.

Here’s how to check if you still have them:

1. Open the Finder.
2. Click Go menu > Go to Folder.
3. Type ~/Library/Application Support and press Return.

Each app’s folder has a corresponding name: you can remove the folders that belong to apps you’ve already deleted.

You can also search for app-related data in these locations:

~/Library/Caches

~/Library/Logs

~/Library/Containers

~/Library/Cookies

Make sure you only delete leftover files; it’s better to keep files of the apps you still use.

What to do if you cannot delete files

• Restart your MacBook.
• Quit all apps running in the background — they may be using a particular file and not letting you remove it.
• Run this Terminal command followed by Return and your admin password:
  sudo rm path to file you want to delete — you can simply drag it to Terminal window. Always double-check that the file you dragged is the one you want to remove.

By now, you should have reclaimed some space classified under System Data. If you want to free up even more storage, follow additional cleanup steps below. 

4. Remove Time Machine local snapshots

Aside from using CleanMyMac and removing app-related files, another quick way to clear System Data on a Mac is to get rid of Time Machine snapshots. Wait, what? You thought Time Machine backups were stored on an external or network drive? They are! But macOS also keeps local snapshots on your startup drive: Time Machine saves one about every hour and keeps it for 24 hours. That way, you can restore data on a MacBook even when you’re on the move.

Time Machine deletes local snapshots automatically as they age or when space is needed for other things, and your Mac counts the space they use as available storage. And besides, you might not want to wait until your Mac is short of space before you delete them. Here’s how to remove them in Terminal. Remember, that will remove the local snapshots, so if you think you might need them, don’t do it.

1. Open Terminal and paste tmutil listlocalsnapshotdates / with the space before /.
2. Press Return and wait until you see the list of snapshots.
3. Type tmutil deletelocalsnapshots followed by one of the listed dates. Each date takes the form YYYY-MM-DD-HHMMSS.
4. Press Return.
5. Repeat steps 3 and 4 for as many snapshots as you want to remove. To check that they are gone, run tmutil listlocalsnapshotdates / again.

Once you’ve removed local snapshots, you may want to prevent the creation of new ones. Keep in mind that this also stops Time Machine from backing up your Mac automatically until you turn automatic backups on again. To do it, follow these steps:

1. Go to System Settings > General > Time Machine.
2. Click Options, choose Manually from the Backup Frequency menu, then click Done.

You can always turn them on later from System Settings.

What to do if you cannot delete Time Machine snapshots? Disable automatic backups as described above and enable them again after a few minutes.

Tip: Remove Spotlight index while in Terminal 

Did you know that Spotlight index can take up gigabytes of space? To check its size, run this command in Terminal:

sudo du -hs /System/Volumes/Data/.Spotlight-V100/ to check the size of the Spotlight-V100 folder that stores the Spotlight index (you will need to enter your admin password)

To rebuild the index, use Apple’s method: go to System Settings > Spotlight > Search Privacy. Click +, add Macintosh HD to the list, wait a few seconds, then remove it by clicking the “-” button, and click Done. Spotlight then reindexes the disk, which can take hours or even days, depending on how much data you have.

5. Optimize your storage

If you’ve faced a cluttered storage situation, there’s another way to fix it. Apple has anticipated such an issue and equipped macOS with some features to optimize your space. Storage settings count the files these options remove under categories, such as Documents, Photos, Messages, TV, and Trash, not System Data, but they still free up space.

macOS Ventura and later

Go to the Apple menu and select About This Mac > More Info. Select Storage Settings. 

In the window that appears, you can see some useful suggestions. “Store in iCloud” lets you keep files, photos, and messages in iCloud and save space on your Mac. Optimize Storage removes movies and TV shows you’ve already watched.

Turning on “Empty Trash Automatically” can be a useful option if you forget to do it regularly. It permanently erases items that have been in the Trash for more than 30 days.

By clicking the I icon next to Documents under Recommendations, you will jump into the Documents section. Review the files that are stored on your Mac and pay attention to the Unsupported Apps category. It can contain some apps that can no longer run on your macOS version.

Pre-Ventura

If you're still running macOS Monterey or older, the steps for optimizing storage are a bit different. Here's what you need to do: 

1. Go to the main Apple menu and choose About This Mac.
2. Click Storage > Manage.
3. In a window that opens, work your way through the recommendations. 

6. Clean up your Downloads folder

The Downloads folder is a place we all rarely clean up. Eventually, it gets filled with all sorts of items — photos, movies, PDFs, installers, and dusty files you downloaded a long time ago. Storage settings count them under Documents, not System Data, but clearing them still frees up space. Here’s how to clear them up:

1. Go to Finder > Downloads.
2. Sort by Size by clicking arrows next to the Size column. 

The largest files will appear on the top of your list — move the ones you don’t need to the Trash.

To find out what else takes up space, you’ll need to browse your storage. The easiest way to do it is to use CleanMyMac. This app has a tool named My Clutter that scans your Mac for large files that you haven’t opened for a while. It can also find similar images, duplicates, and app downloads. Basically, CleanMyMac can do the browsing for you:

1. Get started with a free CleanMyMac trial.
2. Install and open the app.
3. Click My Clutter > Scan > Review All Files.
4. Review the files it found, select what you want to delete, and click Remove.

7. Delete iOS backups

Another space hogger is old iOS backups, which Storage Settings lists under iOS Files rather than System Data. If you don’t use your Mac for backing up your mobile devices, like iPhone, iPad, or iPod touch, you don’t need to follow these steps. If you do, here’s how to delete old iOS backups: 

1. Go to System Settings > General > Storage. 
2. Find iOS Files on the list under Recommendations and the colored graph, then click the Info button next to it.
3. Select the backup you want to remove and click Delete. Make sure to keep the latest backup for each device that you back up to your Mac. 
4. Once you’ve removed unneeded backups, click Done and quit System Settings.  

There is another way to remove iOS backups: 

1. From the Finder, click Go > Go to Folder.
2. Copy and paste the following path and press Return: ~/Library/Application Support/MobileSync/Backup
3. Send unneeded backups to trash and empty it. Don’t forget to keep the latest backup for each device. If you’re not sure which backup belongs to which device, use the Finder instead: connect the device to your Mac with a cable, click it in the Finder sidebar, click Manage Backups in the General tab, then right-click the backup you want to remove and choose Delete.

Or you can use CleanMyMac’s Cleanup tool as described above — it finds unnecessary iOS backups and safely removes them.

What to do if you cannot delete iOS backups from Mac

• Make sure you are not restoring an iPhone from a backup you are trying to remove.
• Check if a backup is locked (press Command + I and see if the checkbox next to Locked (under General) is selected) and unlock it if it is.
• Ensure that the name of the backup does not contain special characters — rename it if it does.   

Why System Data won’t decrease

So, you’ve followed all the steps above, and System Data still won’t decrease? Make sure that you’ve emptied the Trash, especially after manual cleaning. If you have multiple apps open in the background, it may be that they have already re-created their cache files, and these files continue to take up space you thought you’ve reclaimed. 

System Data storage can occupy tens of gigabytes of space on your Mac for cache, logs, and other similar files. macOS manages these files itself, and Storage settings don’t let you manage System Data directly. But if you want to do a System Data cleanup or just free up more space on your Mac, follow the tips above. You might be surprised by how much space you get back.