Delete old iPhone backups from your Mac
~/Library/Application Support/MobileSync/Backup.
The supported way
- Connect any device, open it in Finder (or just open Finder → General tab for a connected device).
- Click Manage Backups… – you'll see every backup with its date.
- Select the stale ones → Delete Backup.
No device at hand? The folder route works too:
du -sh ~/Library/Application\ Support/MobileSync/Backup/*
Each hash-named folder is one device. The device name is inside its
Info.plist. Deleting a folder deletes that backup.
What you lose
⚠️ A backup is the only copy of that device's state at that moment – once deleted it is gone for good. Keep the latest backup of devices you still own; delete backups of devices you no longer have (they can never be restored to anything anyway... unless you buy the same model and want your old data back).
Note: macOS may need permission
MobileSync is protected – Terminal or third-party apps need Full Disk Access (System Settings → Privacy & Security) to even see the folder sizes.
CacheCleaner (full version) lists each backup by device name with its real size, marked with ⚠️ and never pre-selected – deleting a backup is a decision, not a default.
Get CacheCleaner for Mac