How to Clear System Data on Mac?

Set optimize iCloud Drive or iCloud Photos ON, so those files are automatically replaced by placeholders or smaller thumbnails if the Mac's local storage is too full. You can also "Remove Download" to do that manually to iCloud Drive items (although I miss a feature to do that en masse -- nowadays I must do it manually to selected not too many folders and files at a time).

If you are talking about System Data itself, do not look at it because it is an unreliable mess. Instead check free space via Disk Utility or Finder's Status bar.

You might try to decrease System data via a detour to Safe boot and by deleting snapshots via Disk Utility but macOS should take care of that automatically.

System Data Cannot Be Fully Cleared Manually

•On macOS Ventura, Sonoma, and newer, System Data includes critical system components (swap files, caches, snapshots, indexes).

Apple restricts direct user access because improper deletion could break macOS.

Best practice: Free space around System Data by removing unnecessary files, allowing the system to shrink System Data naturally during maintenance.

2. Why iCloud Storage Does Not Free Local Space

•Paying for iCloud expands cloud storage, not local disk storage.

•macOS uses Optimized Storage, keeping essential or frequently accessed files physically on the Mac.

•System files, cached photos, mail attachments, and messages still occupy local space.

•Therefore, even with iCloud, local disk usage remains significant unless actively managed.

3. Methods to Free Local Storage

•Turn on Optimize Mac Storage for iCloud Drive and Photos.

•Manually offload large iCloud Drive files using “Remove Download.”

•Clear Mail attachments by erasing junk/deleted items and limiting downloads to “Recent.”

•Review and delete Messages attachments.

•Clean System Data safely by clearing caches, old backups, unused apps, and local Time Machine snapshots.

4. If Storage Issues Persist

• Consider upgrading internal storage (if your model permits).

• Move large files (Photos, Videos) to an external drive.

• Remove unused applications.

• As a last resort, perform a clean macOS reinstall if space usage remains unusually high.

efstgr wrote:

I saw older posts that don’t work anymore, can anyone tell me how to Clear System Data on Mac? Also I pay $2.99 every month to have more iCloud space and my mac says I don’t have any more local space. Since everything is backed up in iCloud why I don’t have any more local space? how is this possible?

Why, exactly, do you need to the " Clear System Data " Volume ?

Be aware the System Data is really and has the Mount Point of /System/Volume/Data

As such, it is part of the Operating System once you have created a User Account ( Home folder ) on this computer

As for iCloud

It is a conduit to have files Both On the Internal Drive and also on iCloud

With this setup you can make changes to files On the Computer and the changes are reflected to the files on iCloud

Those same charged files on iCloud can be accessed by Other Devices you have that use the Same Apple Account

The thing that many people misunderstand, is that iCloud was not designed or intended to be like a Archive to Off Load files from the computer in-order to Make Space on the Internal Drive

That is best left to an Cloud Based Storage Service or better still to an External Drive

So we come back to the original question >> "Why, exactly, do you need to the " Clear System Data " Volume ? "