iPhone backups on Mac taking up space: safe to delete old ones?
Where it is
~/Library/Application Support/MobileSync/Backup
⏱ Only items untouched for 30 days
What it is
When you back up an iPhone or iPad to your Mac through Finder (or iTunes on older macOS versions), the full backup is saved as a folder with a long device-specific name inside MobileSync/Backup. It contains messages, app data, settings and any photos that aren't in iCloud.
Why it gets so big
A local backup can be nearly as large as the data on the device. Archived backups, devices you've since replaced, and family members' devices all keep their backups until you remove them.
Is it safe to delete?
Review before deleting: a backup may be the only copy of whatever it contains that isn't in iCloud. Backups of devices you no longer own, or older archived backups, are generally fine to remove. Keep the latest backup of each device you still use, and be extra careful if a device was lost or wiped.
Tip
Finder's Manage Backups button, in a connected device's General tab, lists backups by device name and date, so you can tell which folder is which.
See how much space it uses
du -sh "$HOME/Library/Application Support/MobileSync/Backup" 2>/dev/nullDelete it by hand
Run in Terminal. Deleting cannot be undone, so check the paths first.
find "$HOME/Library/Application Support/MobileSync/Backup" -mindepth 1 -maxdepth 1 -mtime +30 -print