Why is my Mac still full after deleting files?
Space returns only when the Trash is emptied, and Storage settings can lag for a while. Purgeable space and local snapshots can also hold the figure. Empty the Trash, wait a minute, and compare again.
Read the guide: Mac storage not updating after deleting files?
What should I clear first when storage is full?
The Trash, the Downloads folder, old installers in Applications and superseded iPhone backups. Those return the most space with the least risk, before you touch anything in the Library.
Read the guide: Mac storage full: first steps when the disk is almost full
Why does a macOS update say there is not enough space?
The installer needs more room than its download, because it unpacks and macOS stages files while installing. Clear what you recognise, prefer Software Update to a full installer, and use Apple’s safe mode trick for a temporary boost.
Read the guide: Not enough space to update macOS: what to free first
What is purgeable space, and can I clear it?
Files macOS can remove itself when it needs the room, already counted inside the available figure. You cannot empty it by hand, and you rarely need to; it is released as space is required.
Read the guide: Purgeable space on Mac: what it means and what to do
Why do two tools show different free space?
Storage settings reports available space, which can include purgeable space; Terminal and some tools report free space, which does not. Both are right; they answer different questions.
Read the guide: Mac storage glossary: System Data, purgeable space and more
What if the Trash will not empty?
Read the message: a locked file needs unlocking with Get Info, a file in use needs its app quit, and an item from an external drive needs that drive connected. Delete Immediately handles a single stubborn item.
Read the guide: Trash won’t empty on Mac: locked, in use or on another disk
How do I check what is using my Mac’s storage?
System Settings → General → Storage shows the bar and its categories; each category has an information button that lists its contents by size. What the categories hide needs Terminal or a scanner.
Read the guide: How to check storage on Mac and see what uses the space
Why is storage full right after a macOS update?
The update leaves a local snapshot of the previous system, the installer app if you used one, and caches the system rebuilds. Most of it clears itself within days; the installer does not.
Read the guide: Mac storage full after a macOS update: what changed
Is the Downloads folder worth clearing?
Usually yes. It fills with installers, disk images and archives whose job is done. Sort it by size, delete by type, empty the Trash, and set Safari to ask where each download goes.
Read the guide: Clear the Downloads folder on Mac without losing anything
Should I turn on Apple’s Optimize Storage recommendations?
They are three separate switches with different costs: two move files into iCloud on demand and count against your iCloud plan, one empties the Trash on a 30-day timer. Turn on the ones whose cost you accept.
Read the guide: Optimize Storage on Mac: what each recommendation does