Your iPhone Backups Are Hiding on Your Mac — Here's Where

If you’ve ever backed up an iPhone or iPad to your Mac through Finder — or its predecessor, iTunes — that backup is still sitting on disk, at full size, even if you upgraded phones twice since.

du -sh ~/Library/Application\ Support/MobileSync/Backup/*

A single unencrypted iPhone backup typically runs 5–15 GB; with Health data, message history, and photos not in iCloud included, 20–40 GB per backup isn’t unusual. Two or three backups from old devices you’ve since sold or replaced can easily be 60+ GB of pure dead weight.

Finding out which backup belongs to which phone

Each backup folder is named after a device identifier, not a phone name, so you can’t tell which is which just by looking:

ls ~/Library/Application\ Support/MobileSync/Backup/
# 00008030-001A2C3D4E5F6001  00008110-000C48A82246C01E  ...

Open Finder → your iPhone (when connected) → Manage Backups, or in older macOS, iTunes → Preferences → Devices, to see a list of backups with device names and dates attached — this is the easiest way to identify which folder on disk corresponds to which phone before you delete anything.

Alternatively, each backup folder contains an Info.plist with the device name in it:

plutil -p ~/Library/Application\ Support/MobileSync/Backup/00008030-001A2C3D4E5F6001/Info.plist | grep "Display Name"

Deleting old backups

Once you know which backup belongs to a device you no longer own, or a backup superseded by a newer one of the same device, deleting the folder is safe and immediate:

rm -rf ~/Library/Application\ Support/MobileSync/Backup/00008030-001A2C3D4E5F6001

The same Manage Backups panel in Finder has a Delete Backup button that does the same thing more safely — it won’t let you delete the backup for a currently-connected device by accident, which a raw rm -rf will happily do.

The one real risk here: if a backup is your only copy of data that isn’t in iCloud — messages older than what iCloud syncs, an app’s local data that never uploaded — deleting it is genuinely unrecoverable, unlike almost everything else in this article’s series, which regenerates from source. Before deleting, ask specifically: is there a newer backup of the same device? If yes, the older one is safe. If a device’s only backup is the one you’re about to delete, make sure you’re actually done with that phone.

Encrypted backups take more space, not less

If you enabled “Encrypt local backup” for a device, that backup additionally includes Health and Keychain data that unencrypted backups skip — meaning encrypted backups typically run 20–40% larger than an unencrypted backup of the same phone. Worth knowing before you’re surprised by the size difference between two backups of what feels like the same amount of phone data.

What replaced this for most people

If you’re on iCloud Backup for your current phone, Finder-based local backups may not be something you’ve made in years — but they don’t expire or get pruned on their own, so whatever you made the last time you plugged a phone into this Mac for a manual backup is exactly as large today as it was then. It’s worth checking this folder even if you’re fairly sure you don’t use local backups anymore; plenty of people made exactly one, years ago, before switching to iCloud, and forgot.

DevCruft, a free Mac app we’re building for developers, is being designed to find every MobileSync backup on your disk, show the device name and date for each without hunting through Finder’s Manage Backups panel, and flag backups superseded by a newer one of the same device. It isn’t released yet, so use the commands above for now — they’re free and they work. Join the waitlist if you’d like a note when it’s out.

For the other large, easy-to-forget storage categories on a Mac that has nothing to do with development work, see what macOS’s “System Data” category actually contains.