Help · Mac storage
Optimise Storage on a Mac: what each setting does.
In System Settings › General › Storage, macOS offers a few one-click recommendations. They're genuinely useful, but each one changes how your Mac handles files from then on, so it's worth knowing what you're turning on, and how to turn it off again.
Store in iCloud
What it does: puts your Desktop and Documents folders in iCloud Drive, your photos and videos in iCloud Photos, and your messages in iCloud. When space is needed, only recently opened files stay fully on your Mac; older ones download when you open them.
- Good for: a Mac with a small disk, if you have enough iCloud storage.
- Watch out: you need an internet connection to open older files, and your iCloud plan has to be big enough.
- To undo: it's three separate settings. Turn off Desktop & Documents Folders and Optimise Mac Storage in System Settings › [your name] › iCloud › Drive. Choose Download Originals to this Mac in Photos › Settings › iCloud. Turn off Enable Messages in iCloud in Messages › Settings › iMessage. Make sure you have room for everything to come back first.
Optimise Storage
What it does: removes Apple TV films and shows you've already watched, and keeps only recent email attachments on your Mac when space is needed. Purchases can be downloaded again.
- To undo: in the TV app, choose TV › Settings › Files and turn off Automatically delete watched movies and TV shows. In Mail, choose Mail › Settings › Accounts, select an account, and set Download Attachments to All.
Empty Trash Automatically
What it does: permanently deletes anything that's been in the Trash for more than 30 days.
- Watch out: if you use the Trash as a “maybe” pile, things will disappear for good after 30 days. (Items deleted from iCloud Drive are always removed after 30 days anyway.)
- To undo: in Finder, choose Finder › Settings › Advanced and turn off Remove items from the Trash after 30 days.
What macOS does without asking
macOS already clears some things by itself when space runs low: caches, logs, interrupted downloads, staged updates and similar temporary files. You don't need to do anything for those.
Beyond the recommendations
Click the ⓘ next to each category in Storage settings (Applications, Documents, Mail, Messages, Music Creation and others) to see what's there. Some let you delete items directly; Other Users & Shared, macOS and System Data don't. For System Data, see what System Data is.
See past the categories.
Pangalin Space Manager shows your disk folder by folder, including what macOS lumps into System Data, and opens macOS's own Storage settings when Apple's tools are the right answer. Every change it makes is shown first, and most can be undone.
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