This can be a problem if your Mac has low storage – you may see a message that your start-up disk is almost full, for example, and if you ignore that you may not be able to turn on your Mac! Low storage can also slow down your Mac and cause other problems by stopping it from running properly. You may also find that you cannot install an update on macOS if you do not have enough free storage.
If you’re struggling with not having enough storage on your Mac, you’re wondering what you can delete. Apple offers ways to make this process easier (read how to make more space on your Mac). If you click on the Apple logo> About this Mac and select Storage, you will see an image like this:
This graph shows how much of your storage is responsible for certain types of files on your Mac. As you can see from the picture above: The system is using up to 19.63GB on our Mac. We’ve heard that people who have too much space are being blamed for the system.
Note that in some versions of macOS the data types are labeled separately. For example, macOS Monterey may have been preceded by many other places (we discuss how to delete other storage on a Mac in a separate article). Similarly, instead of systems, you may see a section of storage labeled as system data and another section labeled MacOS. It’s basically the same thing: files that don’t fall into other categories, usually data and files used by MacOS, cache, temporary files, backups, plug-ins, etc.
It is also possible that you do not see any system or other, or any other unknown section of storage. But that doesn’t mean you can’t follow the steps below to free up some space on your Mac.
If you have limited storage, you will look for ways to reduce it, and if this type of storage takes up a lot of space, you hope you can delete it. Read on to find out how you can recover the space it occupies.
If you’re not sure how much disk space your Mac will have: How to check how much disk space you have.
What’s in a Mac Storage System?
System (or system data) is a catch-all title for the various components scattered across your Mac’s drive. This usually includes old time machine snapshots, iOS backups, cached files, any downloaded disk image for app or MacOS upgrade, and its files will appear on the system if you enable the FileVault encryption feature.
We also have an article that explains how to delete a Mac cache.
How much space is the system taking up?
To get an idea of the space used by system files, take the following steps:
- Click on the Apple logo in the upper left corner of the screen
- Select about this Mac.
- In the small window that appears, click the Storage tab
You will see a graphic explaining how your disk space is being allocated. The system is gray and will reveal the shape if you hover the mouse cursor over the area. For a more detailed breakdown, click the Manage … button, which opens a new window with the various components listed with the storage space they’re using.
You will see the system at the bottom of the left hand column, but, unlike the rest of the list, clicking on it will not reveal which files are being assigned to the system. This means you are on your own in terms of cleaning. (You won’t see the system in the latest version of MacOS).
If you see another section whose name replaces another disk and you want to fix it and read how to delete other storage on Mac.
Why is there so much system storage on my Mac?
It all depends on what file you have on your Mac. If you have a lot of time machine snapshots or iOS backups, it can often cause a big build up in the system.
When you turn on Storage Overview about this Mac, it’s worth waiting a few minutes before deciding that the system is receiving an obscene amount of storage. Apparently it can re-adjust itself after a few minutes when some of the things charged on the system are transferred to iCloud or somewhere else (although unfortunately this did not happen in our case).
Can I delete my Mac’s system storage?
MacOS does not have a clear system or delete system button, so you need to manage the storage yourself. In the section below we will explain how to delete each type of system file.
Although it is possible to manually delete the various files included in the system section, we recommend that you know if you know what you are doing. Accidentally deleting an important file is easy, only to find it later causes problems. If the crash strikes, try some tips on how to recover deleted files on Mac.
Also, before deleting anything, we recommend running a full backup of your Mac’s storage so that you can restore it to its original state in case of any problems. Read on for more details on how to backup a Mac and the best Mac backup software.
Alternatively the safer option would be to use a system clean-up app such as MacPaw’s CleanMyMac X or Nektony’s MacCleaner Pro. You can find reviews of those tools in a roundup of our best Mac Cleaner software and optimization utilities. These apps can safely delete files you don’t need, so you don’t have to worry about finding and identifying deleted secure files.
How To Remove Time Machine Snapshots On Mac
One of the main culprits of taking place in the system is the local snapshot time machine created every day. You might think that time machine backups are only stored on an external disk, but Apple also creates local snapshots in your startup volume. The company says that these snapshots will only be saved if there is plenty of free space, and that old snapshots will be automatically deleted when new ones are created.
If you accidentally save the correct changes to a document or delete something you don’t want, it could replace your Mac that you would like to access.
Luckily there is an easy way to remove local snapshots from your hard drive. You can simply turn off the Time Machine feature manually, which will remove all local snapshots stored on your Mac. There are also some complex methods using terminals. We explain both in our step-by-step guide to removing these pattern-stealing patterns, so read How to Delete Time Machine Backups on Mac to find an easy way to remove them.
How To Remove Old iOS Backups On Mac
Another hogger of system space is the old backup of your iPhone or iPad. These can use up unnecessary space on your Mac, so it’s a good idea to clean them up all at once. Depending on which version of macOS you are using, here’s how to quickly deliver with them.
macOS Catalina or later
- Open Finder
- Click on your iPhone in the menu on the left
- Select Manage Backup …
- You no longer need highlights
- Click Delete Backup then confirm your choice
macOS Mojave or earlier
- Open iTunes
- Select iTunes (in the top left corner) then Preferences
- Select the Devices tab from the window that appears
- Highlight backups you no longer need
- Click Delete Backup
How to find the system folder on Mac
It takes care of the two biggest users of Mac’s system storage, what about everything else?
MacOS systems and libraries prefer to hide folders, perhaps to prevent users from accidentally moving or deleting necessary files. But if you want to access that part of your storage, it is possible through a menu option in Finder.
To grant yourself temporary access, use the following steps:
- Open a new Finder window
- Go to your home folder (press Command + Shift + H)
- Right-click and select View Options from the menu
- Enable the option to show the library folder
You will now be able to open the folder and look for files that you suspect are taking up space on your drive. There are actually multiple ways to make the Hidden Library folder visible, read: How to show hidden files on Mac for more details on finding hidden files.
The important thing is to be careful and only delete things that you know are unnecessary.
We think the best option is to really use a dedicated optimization utility, so take a look at our guide to the best Mac cleaner software and optimization utilities as it provides the easiest way to keep your Mac in tip-top condition. You can also reduce the amount of storage stored on your device by following the tips on how to free up space on a Mac.
When we were trying to install MacOS Big Sur we wanted to reclaim the storage space we relied on CleanMyX X which has a tool for cleaning System junk. CleanMyMac X is now 29.95 / £ 29.95 if you bought the plan for a Mac. There is also a free trial. Download from developer MacPaw here.