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How to back up your photos on a Mac

Updated

The simplest way to back up photos on a Mac is Time Machine, which is built into macOS and saves a copy of your Mac to an external drive. Plug in the drive, turn it on in System Settings, and it keeps going on its own.

If you use iCloud Photos, that’s not enough on its own. Apple’s Photos guide says: “Even if you use iCloud Photos, it’s important that you always back up your photo library locally.”

Before you start

  • You need an external drive. Apple recommends one with at least twice the storage of your Mac, used only for Time Machine. For a 1 TB Mac, that means 2 TB or more.
  • The first backup can take hours. Leave the Mac plugged in.
  • Time Machine will offer to erase the drive. Anything already on it will be lost, so copy off what you need first.

Set up Time Machine

  1. Connect the external drive.
  2. Choose Apple menu > System Settings.
  3. Click General in the sidebar, then click Time Machine.
  4. Click Add Backup Disk and select your drive.
  5. Click Set Up Disk. When asked, turn on Encrypt Backup and write the password down somewhere safe. You’ll need it to restore anything.

Backups start straight away. Apple says Time Machine keeps hourly backups for the past 24 hours, daily backups for the past month and weekly backups after that. The oldest are deleted when the drive fills up.

The drive has to be plugged in for this to work. Eject it before you unplug it.

iCloud Photos is not a backup

iCloud Photos keeps the same photos on all your devices. That’s useful, but it means a deletion on one device happens on all of them. Apple’s guide says that “when you delete files from your System Photo Library, they’re also deleted from iCloud.” Deleted items stay in Recently Deleted for 30 days, and after that they’re gone.

That’s a sync service, not a second copy. If a photo is deleted by accident, by a child, or by an iPhone clean-up, it disappears from the Mac, the iPhone and iCloud.

If you want the full library on the Mac

By default the Mac may keep only small versions of your photos to save space. Time Machine can only back up what’s on the Mac, so check this setting:

  1. Open Photos.
  2. Choose Photos > Settings, then click iCloud.
  3. Under iCloud Photos, select Download Originals to this Mac.

Apple says this keeps full-size versions of your photos on the Mac and in iCloud. Wait for the download to finish before relying on your backup, and make sure the Mac has enough room. If you want the iCloud side explained, see how to download all your photos from iCloud.

Apple also warns that image files stored outside your photo library, called referenced files, are not included when you back up the library. Photos files that live in other folders need backing up separately.

The 3-2-1 idea, in plain words

  • Three copies of anything you can’t replace. The original plus two more.
  • Two kinds of storage. For example, your Mac’s drive and an external drive. Two drives bought on the same day can fail in the same way, so mix them up.
  • One copy somewhere else. This protects you from fire, theft and flood. It could be a drive kept at a relative’s house, or an online service.

For most people, that looks like this: photos on the Mac (copy one), Time Machine on an external drive (copy two), and a second drive or a cloud copy kept away from home (copy three).

Check that the backup holds your photos

A backup nobody has looked at is a guess. Check it once.

  1. Connect your Time Machine drive.
  2. Click the Time Machine icon in the menu bar and choose Back Up Now. The same menu shows the time of the latest backup.
  3. Wait for it to finish, then look at the drive in Finder. You should see a folder for your backups.
  4. To see what’s in a backup, follow Apple’s Time Machine restore guide and look through the categories in Migration Assistant. If your Photos library is there, so are your pictures.

If you use Optimize Mac Storage, a restore may not bring back full-size originals. That’s one more reason to choose Download Originals to this Mac.

You can also copy the Photos library by hand: in Finder, open Pictures and drag the library onto an external drive. Apple lists this as an alternative to Time Machine. Don’t put the library on the same drive that holds your Time Machine backup.

If you’re a Photo Organizing Co client

You don’t need to set up a backup before I start. But please don’t delete anything from your Mac, phone or iCloud account until the finished library is on your drive and you’ve looked through it. If you already have a Time Machine drive, tell me, and keep it plugged in somewhere safe. I’ll work from copies and leave your originals alone.

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