Mac storage full but nothing to delete? Where to look

Why your folders look small while the disk is full

Finder opens on your home folder and shows Desktop, Documents, Downloads, Movies, Music and Pictures. Those are the folders you fill on purpose. Apps and macOS fill a different set, and Finder hides most of them so they are not deleted by accident.

So adding up the folders you can see gives a number far below what the disk reports. The difference is real data. It is just somewhere else.

• ~/Library, hidden by default, holds app data, caches, mail, messages, phone backups and developer files.
• Hidden folders whose names start with a dot, such as ~/.cache or ~/.docker, are used by command-line tools.
• Local snapshots keep files you already deleted until they expire.
• Other user accounts on the Mac have their own home folders that you cannot open.
• Swap files and the sleep image belong to macOS and grow when memory is under pressure.

Start with Storage in System Settings

Open the Apple menu, choose System Settings, then General, then Storage. Wait for the bar to finish calculating, then read the rows below it from largest to smallest.

If Applications, Documents, Photos or Messages is the largest, click its info button and work from the list it shows. If System Data is the largest, that is your answer to the puzzle: System Data is everything macOS cannot label, it has no info button, and it is where the hidden folders above are counted.

Empty every Trash, not just the one in the Dock

Files in the Trash still take up space until you empty it. Right-click the Trash in the Dock and choose Empty Trash, after a quick look at what is in it.

Some apps keep their own. Photos has a Recently Deleted album that holds items for 30 days. Mail keeps deleted messages in each account's Trash mailbox until you choose Mailbox, then Erase Deleted Items. Emptying these is permanent, so check them first.

Look inside the hidden Library folder

In Finder, open the Go menu and hold the Option key. Library appears in the list. To see hidden dot folders in any Finder window, press Shift, Command and Period.

Finder does not show folder sizes unless you ask, so Terminal is quicker here. The command below lists the folders in your Library by size, largest last. It only reads. macOS may ask whether Terminal can access some folders, and it reports nothing for folders it is not allowed to read.

The usual large ones are Caches, Application Support, Containers, Group Containers, Developer, Messages and Mail. Caches can be cleared with the apps closed. The others hold real data, so use the size to decide which app to tidy from the inside, not which folder to delete.

du -sh ~/Library/* 2>/dev/null | sort -h | tail -15

Check for snapshots holding deleted files

If you have already deleted a lot and free space did not move, a local snapshot is probably holding the data. Time Machine takes these snapshots on your startup disk, and anything you delete stays on disk until the snapshot that includes it expires, usually within a day.

The command below lists them and deletes nothing. If the list is long and you need the room now, wait a day, or see our guide to local snapshots before removing any.

tmutil listlocalsnapshots /

Check other user accounts and shared folders

Open System Settings and choose Users & Groups. Every account listed has its own home folder, with its own photos, downloads and Library. An old account from a previous owner or a family member can hold a large share of the disk without showing up anywhere in your own folders.

You cannot look inside another account's folders, but the Storage screen may list Other Users and Shared. The command below shows the size of the Shared folder, which every account can write to. To free an old account's space, an administrator can delete the account in Users & Groups and choose to delete its home folder. That removes all of that person's files, so make sure nobody needs them.

du -sh /Users/Shared 2>/dev/null

Restart before you conclude anything

A restart clears swap files, temporary files that are no longer in use, and caches macOS only releases at startup. On a Mac that has been running for weeks with many apps open, this alone can return a noticeable amount of space.

After restarting, open Storage again. If the figure dropped, memory pressure was part of the cause. If it did not, the space is in files, and the steps above will find them.

Seeing all of it at once with Diskzy

Diskzy maps the whole disk, hidden folders included, so the places described here appear with their sizes next to the folders you already know. Its System Data view breaks that category into named parts such as caches, app data, developer data, logs, backups and swap, each sized and marked Safe to clear, Look first or Managed by macOS.

It needs Full Disk Access to see everything. Anything you remove with it goes to the Trash, so nothing is gone until you empty the Trash.