Why is my Mac storage full?

See what’s using the space

1. Choose Apple menu, System Settings, click General in the sidebar, then Storage. On macOS 12 and earlier: About This Mac, Storage.
2. Wait for the bar to finish. Each category below it shows its size; categories with an Info button (Applications, Documents, Messages, TV, Music Creation, Trash and others) list the files so you can delete them there.
3. Check the recommendations at the top: Store in iCloud, Optimize Storage and Empty Trash Automatically.

Apple says the numbers update automatically as you free up space, so you can watch the bar change.

Common causes, and what to do

Photos, videos, downloads and old backups

Apple’s list of what to clear first: move big media to an external drive, delete movies and music you can download or stream again, clear out the Downloads folder, delete junk and deleted mail in Mail, remove apps you don’t use, and delete old iPhone or iPad backups. Compressing files you rarely open saves space without deleting them.

System Data is huge, and there’s “nothing on it”

System Data (called Other on older macOS) is, in Apple’s words, Apple and third-party files that don’t belong to a more specific category. Apple doesn’t itemize it, but says that when space is needed, macOS clears caches and logs that are safe to delete on its own: temporary database files, interrupted downloads, staged macOS and app updates, and Safari website data. So part of what you see there is space macOS gives back when it needs room.

What to do: work through the categories you control first; that’s where Apple’s tools point. Starting up in safe mode once also clears some system caches, which rebuild as needed. Don’t delete files from system folders by hand.

Space didn’t come back after deleting

• The Trash: moving a file to the Trash doesn’t free its space. Empty it (Finder, Empty Trash), or turn on Empty Trash Automatically, which erases items after 30 days.
• Photos: deleted photos and videos stay in Recently Deleted for 30 days. Empty Recently Deleted in Photos to get the space now.
• Time Machine snapshots: Time Machine keeps local snapshots, but Apple says your Mac counts their space as available, and removes them as they age or when space is needed. They don’t make the disk full.

iCloud storage and Mac storage are two different things

An “iCloud storage is full” message is about your iCloud plan (5 GB comes free), not your Mac’s disk. When iCloud is full, backups and iCloud Photos uploads stop and iCloud Drive stops staying up to date. Check it in System Settings, your name, iCloud.

To free space on the Mac using iCloud, turn on Store in iCloud in Storage settings: Desktop and Documents go to iCloud Drive and photos to iCloud Photos, and when space is needed only recently opened files stay on the Mac. If space isn’t needed, Apple says the full contents of iCloud Drive stay on the Mac. Careful: deleting a file in iCloud Drive deletes it on all your devices, so it frees iCloud space, not just Mac space.

Why a full disk slows the Mac down

Low free space on the startup disk is the first cause on Apple’s list for a Mac that runs slowly. macOS uses disk space as swap when memory runs short, and needs room for updates. See Why is my Mac so slow? for the other causes.

Keep an eye on it from the menu bar

Storage settings tell you what’s using the space when you go and look. A Disk Space meter in Multimeter shows how full the disk is all the time:

• Percent used for the startup disk or any drive you pick. Its menu shows what’s left, like “120 GB available”.
• Purgeable space counts as free, the way Finder counts it, so the meter agrees with Finder. Terminal’s df doesn’t count purgeable space as free, so it shows less.
• It turns yellow at 85% full and red at 95% by default; change the levels in Customize This Meter…, and turn on a notification for when it goes critical.
• It checks once a minute. An external drive that isn’t plugged in shows as not connected instead of zero.

It shows how full the disk is, not what’s inside; Storage settings has the breakdown. Five live meters use about 3% CPU, and they pause while the displays sleep.