I deleted everything on my Mac and still have 70GB used

If you deleted everything on your Mac and you're still seeing 70GB of used storage, there could be a few reasons for this:

1. System files: macOS requires certain system files to function properly, and these files are not typically visible or accessible to users. These files can take up a significant amount of storage space.

2. Temporary files and caches: Applications generate temporary files and caches during regular use, and these files may not have been deleted when you performed the initial deletion.

3. Trash bin: When you delete files on a Mac, they are moved to the Trash bin. The Trash bin still occupies storage space until you empty it. Ensure that you have emptied the Trash bin after deleting files.

4. Recovery partition: Some Macs have a recovery partition that contains a backup of the macOS installation files. This partition is typically hidden and not visible in Finder, but it can still occupy storage space.

To further investigate and reclaim the storage space, you can try the following steps:

1. Empty the Trash bin: Right-click on the Trash bin icon in the Dock and select "Empty Trash." Confirm the action when prompted.

2. Check system storage: Go to the Apple menu > About This Mac > Storage. Wait for the system to calculate the storage usage. Click on the "Manage..." button, and you'll see a breakdown of what is using up the storage. Look for any large items that you may have missed during the initial deletion.

3. Use a disk-cleaning utility: There are third-party disk-cleaning utilities available, such as CleanMyMac. These applications can scan your system for unnecessary files and help you reclaim storage space.

4. Reinstall macOS: If you performed a reinstallation of macOS instead of a clean wipe, it's possible that the recovery partition is still present. You may need to erase your disk and reinstall macOS from scratch to completely remove all partitions.

If you've tried the above steps and are still experiencing issues with storage usage, it may be worth contacting Apple support or visiting an Apple Store for further assistance.

[Link dited by Moderator]

So just to be clear...you've completed the process outlined here? Erase and reinstall macOS - Apple Support

This sounds like what you're trying to do.

It catches my attention when I see utilities like CleanMyMac mentioned. My experience with them is that they often create more problems than they solve.

So first I'd try uninstalling that app, if you haven't already done so. Tossing the app into the Trash isn't enough, so you'll want to follow the steps linked here: https://cleanmymac.com/how-to-uninstall-cleanmymac#:~:text=You%20can%20remove%20CleanMyMac%20X,CleanMyMac%20X%20for%20complete%20removal.

Are you selling or trading your Mac in? (Just trying to learn why you feel it's necessary to erase the internal storage).

If so, have you completed all the steps in the first part of the article you linked to?

Do you have other users on your Mac? This goes into "other".

Can you describe what it is you did?

MacOS takes up roughly 20GB of internal drive space (give or take...depends on what MacOS you're running, and how much System data your Mac may have stored over time).

When you erased your Mac, did you use a Time Machine backup to put data back onto the device or set it up without a backup?