Troubleshooting & messages · Free space and clean-up messages
Why does Storage Studio say my free space dropped but most of it isn't really gone?
Short answer: A sudden drop is often temporary — an update, a download, or local backups holding deleted files. Storage Studio says when it will come back on its own; check What's Using Space if not.
A sudden drop in free space is often temporary — an app download, an update being unpacked, or your Mac's automatic backups holding files you just deleted. Storage Studio checks what caused it and tells you when most of the drop will come back on its own.
If it doesn't return within a day, open What's Using Space to see what grew.