Where the backups are
Backups you make in Finder (or made in iTunes years ago) all end up in the same folder:
~/Library/Application Support/MobileSync/Backup/
Inside it, every backup is a folder with a long name made of letters and digits, the identifier of the device. You cannot tell from the name which iPhone it belongs to, and the folders inside are not meant to be opened. A single backup is often 10 to 100 GB, and if you have owned a few devices over the years, the folder can hold several of them.
Backups in iCloud are a different thing. They are stored on Apple’s servers, count against your iCloud storage and take no space on your Mac. This guide is only about the local ones.
See how much space they take
In Storage settings
- Choose Apple menu > System Settings, then General, then Storage.
- Wait for the categories to finish calculating.
- Find iOS Files and click its Info button.
The list shows each backup with its size. iOS Files also includes firmware files Finder downloaded to update or restore a device. You can select one and click Delete here, without connecting the device.
In Finder
- Connect the device with a cable and select it in the Finder sidebar. Trust the computer on the device if it asks.
- Click the General tab, then Manage Backups.
This shows every backup on the Mac by device name and date, with a lock next to encrypted ones. It does not show sizes, which is why Storage settings is the better first stop.
In Terminal
The Backup folder is protected by macOS. Terminal can read it only after you give it Full Disk Access in System Settings > Privacy & Security > Full Disk Access. Then this lists each backup with its size:
~ % du -sh ~/Library/Application\ Support/MobileSync/Backup/* 48G …/Backup/00008110-001A2B3C4D5E6F78 31G …/Backup/a1b2c3d4e5f60718293a4b5c6d7e8f9012345678
Without Full Disk Access you see “Operation not permitted”. That is macOS protecting your data, not a broken backup.
Decide which backups to keep
Look at each backup and ask whether you could ever need to restore from it.
- The latest backup of a device you use. Keep it, unless you also back that device up to iCloud and are sure that backup is current.
- Backups of devices you sold, gave away or lost. These are the usual source of wasted space. Keep one only if it holds something you cannot get elsewhere, such as old messages or photos that were never in iCloud.
- Archived backups. Finder’s Archive command keeps a backup from being replaced by the next one. These show a date in their name and are easy to forget. Check whether you still need them.
- Encrypted backups. Encrypted backups also contain saved passwords, Wi-Fi settings and Health data. If a device is still in use, an encrypted backup is the more complete one to keep.
Delete an old backup
The cleanest way is through Finder, because it removes the backup as a whole and keeps the list consistent:
- Connect a device and select it in the Finder sidebar. It does not have to be the device whose backup you remove.
- Click the General tab, then Manage Backups.
- Control-click the backup you no longer need and choose Delete.
- Confirm, then click OK.
The space is freed right away. If you have no device at hand, the Delete button in Storage settings under iOS Files does the same.
You can also remove a backup folder by moving it to the Trash in Finder, but only the whole folder, and only after you know which device it belongs to. The space is freed when you empty the Trash.
Firmware files
When Finder updates or restores a device, it can download a complete copy of iOS or iPadOS, several gigabytes each. These are the firmware files listed under iOS Files in Storage settings. They are safe to delete: Finder downloads them again when it needs them.
Keep backups from piling up
- Use one backup per device. Each new backup of the same device replaces the previous one, unless you archived it. The space grows when you add devices, not when you back up more often.
- Remove backups when you retire a device. Make it part of selling or passing on an old iPhone.
- Consider iCloud backups. If your iCloud storage plan has room, backing up to iCloud keeps the copies off your Mac. You can turn this on in the device’s General tab in Finder or on the device itself.
- Back up to an external drive. Finder always backs up to the folder in your Library. Moving that folder elsewhere with a link is a trick you will find online, but it is fragile and Apple does not support it. Copying old backups to an external drive and deleting them from the Mac is the safer way to keep them.
Questions people ask
Why do I see backups for devices I never connected?
Backups made with iTunes on an older Mac are moved along when you use Migration Assistant. They are real backups and can take a lot of space.
Does deleting a backup affect my iPhone?
No. The device and its data are not touched. You only lose the option to restore from that copy.
Can I open a backup to get one photo out?
Not in Finder. A backup is stored as thousands of renamed files and a database, not as ordinary photos. To get something back, restore the backup to a device. That is one more reason to keep the latest backup of a device you still use.
