Delete Old iPhone Backups on Mac to Free Space

Every time you back up an iPhone or iPad to your Mac, macOS stores a full copy of the device under your user Library — and it never cleans up backups for devices you no longer sync. A couple of forgotten backups can easily hold 50 GB or more. Here's where they live and how to delete them without trashing the wrong thing.

See your device backups and their size

macOS keeps every local device backup in one place: ~/Library/Application Support/MobileSync/Backup. Each backup is a folder with a long hexadecimal name, one per device. To check the total from Terminal:

# Total space used by local iPhone and iPad backups (read-only)
du -sh ~/Library/Application\ Support/MobileSync/Backup

That command only reads sizes; it changes nothing. If you'd rather skip Terminal, open System Settings → General → Storage and look for the iOS Files category — that's the same data, listed per backup with device names and dates. The category only appears when backups exist, so if you don't see it, you have nothing to clean here.

Why so big? A local backup is a near-complete copy of the device: photos not in iCloud, message history, app documents, and settings. Apps themselves aren't included — they re-download from the App Store on restore — but a 256 GB iPhone that's mostly full can still produce a backup of 40 GB or more.

Delete a backup the safe way

1. Open System Settings → General → Storage.
2. Click the ⓘ next to iOS Files.
3. Select a backup and check the device name and date. A backup of a phone you've sold, or one superseded by months of newer backups, is a safe candidate.
4. Click Delete and confirm.

If the device is plugged in, there's a second route: open a Finder window, select the device in the sidebar, stay on the General tab, and click Manage Backups…. Right-click any backup there for Delete Backup and Show in Finder.

Why you shouldn't just trash the folders

You can delete backup folders directly in Finder, but they're named with opaque device identifiers like 00008110-000A2D…, so it's easy to remove the wrong device's backup. The Manage Backups dialog and the Storage pane map names and dates for you — use them. Two more things worth knowing:

• Deleting a backup is permanent. There's no undo; the only way back is making a fresh backup from the device itself. Always keep the newest backup for any device you still own.
• If you do delete folders via Finder, the space isn't actually freed until you empty the Trash.

Stop the pile-up for good

Finder updates a device's existing backup in place, so one active iPhone won't grow this folder forever. The bloat comes from devices you've stopped backing up — the old phone in a drawer, a family iPad, a work device you returned. Your options:

• Back up to iCloud instead. On the iPhone, go to Settings → [your name] → iCloud → iCloud Backup and turn it on. Nothing new lands on your Mac's disk.
• Keep local backups, audit yearly. Local backups restore faster and don't need a paid iCloud plan — just revisit the iOS Files list occasionally and remove backups for retired devices.
• Don't archive unless you mean to. Right-clicking a backup in Manage Backups offers Archive, which freezes that backup so future ones create a new copy. Useful before installing an iOS beta, but it silently doubles the space one device uses.

Still tight on space?

Old device backups are usually the quickest multi-gigabyte win, but they're rarely the only one. Work through the other big space wins on your Mac — snapshots, caches, and forgotten installers add up just as fast.