How to delete old iPhone and iPad backups on a Mac

Where the backups are

Every backup Finder (or iTunes, before macOS Catalina) makes of an iPhone, iPad or iPod touch is kept in one place:

~/Library/Application Support/MobileSync/Backup

Inside it is one folder per backup, named with a long identifier rather than the device's name, which is why the folder tells you nothing on its own. In Finder, press Shift-Command-G and paste the path to open it. To see how much each one holds:

du -sh ~/Library/Application\ Support/MobileSync/Backup/* 2>/dev/null

Terminal may need Full Disk Access (System Settings → Privacy & Security) before it can read the folder. Do not delete a backup from here by hand unless you have to: Finder and Storage settings both know which folder is which device, and you do not.

Deleting a backup from Finder

1. Connect the iPhone or iPad with a cable and select it in the Finder sidebar, under Locations.
2. On the General tab, click Manage Backups.
3. The list shows every backup on this Mac, with the device name and the date it was made. Select the ones you no longer need and click Delete Backup.
4. Right-click a backup to Show in Finder if you want to see its folder, or Archive to keep it dated and out of the way of the next backup.

Manage Backups lists backups of every device, not only the one connected, so one connected iPhone is enough to clear out the backups of phones you no longer have.

Deleting a backup from Storage settings

1. Open System Settings → General → Storage.
2. Click the ⓘ beside iOS Files.
3. Select the backups you no longer need and click Delete.

This is the way to do it with no cable. On macOS Monterey and earlier it is Apple menu → About This Mac → Storage → Manage → iOS Files.

Why Finder backups are so large

A backup to a Mac is a complete copy of the device: every photo and video that is not in iCloud Photos, every message and its attachments, every app's documents and data, and the settings. A phone with 100 GB in use makes a backup not far short of that. Finder keeps one backup per device and updates it in place, so the old backups that pile up are usually the ones you have stopped making: the phone you replaced, the iPad you gave away, the backup you archived before an update and never deleted. Each of those holds its full size for as long as it sits there.

The space is in your own files, so there is nothing to compress or trim. A backup is either kept whole or deleted.

Encrypted backups

If Encrypt local backup was ticked on the General tab when the backup was made, the backup also holds the device's saved passwords, Wi-Fi settings, Health data and website history, and it is the only kind of local backup that does. Deleting one needs no password; the password is for restoring from it. The point to remember is the other way round: an encrypted backup carries things an unencrypted one does not, so if it is the last one of a device you still own, it is worth more than its date suggests.

Which backups to keep

• The newest backup of each device you still own, unless the device also backs up to iCloud. Check on the device: Settings → your name → iCloud → iCloud Backup shows whether it is on and when it last ran.
• The backup you made before a restore or a major update, until the device has been running normally for a while afterwards.
• Nothing else. A backup of a phone you sold, after its replacement has been set up and used, is a copy of data that now lives on the new phone or in iCloud.

A backup cannot be opened as files, so there is no half-measure: you cannot keep the photos from one and discard the rest. If a backup holds the only copy of something, restore it to a device first.

Why it grows back

Because Finder backs the device up again every time you connect it, ifBack up all of the data on your iPhone to this Mac is selected on its General tab. To stop the local copy growing, choose Back up your most important data on your iPhone to iCloud instead, and untick Automatically sync when this iPhone is connected if you plug it in only to charge. The local backup you keep then stays as it is until you make another.

Where the app comes in

RefreshYourMac measures iOS Backups as its own category, rated Backup recommended: it lists each backup with its size, and offers no bulk clean. You pick one at a time, and anything you remove goes to the Trash, where it stays until you empty it; or you use Move to… to put a backup on another drive, which frees the same space and loses nothing. Its own advice is the one above: delete a backup only if the device also backs up to iCloud, or you have a newer one.

If you write apps, two more iPhone-related folders are worth knowing about, because they are not backups and are safe to clear: iOS Device Support, the symbol files Xcode copies from every device you have connected, and iPhone Support Caches, the CoreDevice caches from installing and debugging on a phone. Both are rated Safe for auto removal, and both come back the next time the device is plugged in. iOS Device Support is in both editions; iOS Backups and iPhone Support Caches are in the download only. For the rest of the places worth checking, see how to free up space on a Mac.