How to find and delete old iPhone backups on a Mac

Where the backups are

Finder stores device backups in ~/Library/Application Support/MobileSync/Backup. Each backup is a folder with a long name made of letters and numbers, which says nothing about the device or the date.

A backup can be as large as the data on the device it came from. Finder normally updates the same backup each time, so one device means one folder, but an archived backup or a second device adds another. Several old phones and tablets add up quickly.

See how much space they take

The simplest view is System Settings, General, Storage. If you have backups, an iOS Files row shows their total, and its info button lists each one.

In Terminal, the command below prints the size of each backup folder. It only reads. This folder is protected by macOS, so if you see Operation not permitted, either use the Storage screen or give Terminal access under System Settings, Privacy & Security, Full Disk Access.

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

Decide which backups you still need

A backup is worth keeping only if you might restore from it. Go through the list with these questions.

• Do you still own the device? A backup of a phone you sold or recycled is only useful if it holds something you never moved to the new one.
• Does the device also back up to iCloud? On the iPhone, open Settings, tap your name, then iCloud, then iCloud Backup, and check that it is on and shows a recent date. If so, the copy on the Mac is a second backup.
• Is it encrypted? An encrypted local backup includes saved passwords, Health data and Wi-Fi settings, which makes it more complete than an unencrypted one.
• Is it the newest for that device? Keep the most recent backup of any device you still use, unless it also backs up to iCloud.

Delete a backup in Finder

This is the method Apple documents, and the safest, because Finder shows the device name and date for each backup.

• Connect the iPhone or iPad to the Mac with a cable and unlock it.
• Select the device in the Finder sidebar.
• On the General tab, click Manage Backups.
• Select the backup you no longer need. Check the device name and the date.
• Click Delete Backup and confirm.

Delete a backup without the device

If the device is gone, open System Settings, choose General, then Storage, and click the info button next to iOS Files. The list shows each backup with its size and when it was last used. Select one and click Delete.

The same list can include iOS and iPadOS installer files. Those are always safe to remove, since they can be downloaded again from Apple. Take care to tell them apart from the backups.

Avoid deleting the folders in MobileSync by hand. It works, but the folder names do not tell you which device is which, and a mistake there cannot be undone once the Trash is emptied.

What you lose, and what you do not

Deleting a backup removes the ability to restore that device to the state it was in on that date. Nothing changes on the iPhone or iPad itself, and nothing changes in iCloud.

If the backup was the only place certain data existed, for example messages or app data from an old phone that was never transferred, that data is gone. When in doubt, copy the backup folder to an external drive before deleting it. It can be copied back to the same location later.

Keep backups from building up again

If iCloud Backup is on and working, you may not need local backups at all. They are useful as a second copy before a major iOS update, and you can delete the result afterwards.

In Manage Backups, right-clicking a backup offers Archive. An archived backup is frozen and will not be overwritten by the next one, which is useful before an update but is also how extra copies accumulate. Check the list a couple of times a year.

How Diskzy shows backups

Diskzy shows device backups as their own named part under System Data, with their size, so you can see at a glance whether they are worth your attention. It leaves the choice of which backup to remove to Finder, where each one is shown with its device and date.