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Are your original photos really on your Mac? Check before you turn off iCloud Photos or erase it

By Kayabyte · Last updated 11 November 2026

Short answer: a Photos library on a Mac can hold only smaller copies of your pictures if Optimize Mac Storage is on. Apple says that option keeps smaller versions on the Mac when storage is limited and the full-size originals in iCloud. If you are about to turn off iCloud Photos, copy the library, or move away from a Mac, choose Download Originals to this Mac first and let it finish, then make a copy of the library.

Step 1: See which setting you use

Apple’s page “Use iCloud Photos on Mac” (checked 11 November 2026) says to open Photos, choose Photos, then Settings, click iCloud, and look at the options under iCloud Photos:

If Optimize is selected, the Mac may not hold every original.

Step 2: Download the originals

Choose Download Originals to this Mac and wait. Apple’s page says the download can take a while for a large library. Check that the Mac has room for the full library first: Photos Settings and Finder show the size of the library, and your disk needs more free space than that.

Step 3: Be careful when turning iCloud Photos off

Apple’s page says that if you turn off iCloud Photos on all devices, your photos and videos will be deleted from iCloud in 30 days and you will not be able to recover them unless you undo it before then. Apple’s turn-off steps include a Download button that fetches photos and videos from iCloud to your Mac. Use it, and confirm the originals are on the Mac before you do anything else.

Step 4: Copy the library, then check the copy

Copy the Photos library to an external drive formatted for Mac. Keep the first copy untouched. A copy made while originals were still in iCloud cannot give those originals back, with Photos or with any app that reads the copy, so the order above matters. See how to open a Photos library from an old Mac for opening a copy safely.

A faster way to check: AlbumRescue

AlbumRescue is a Mac app we make. It reads a Photos library without opening or changing it, lists its albums and photos, and has a Missing or Limited list that gives each item with no full original in the copy, with the reason. A video may have only a still picture. You can run it on the copy before you erase anything. It can compare the copy with another library and save a CSV report that lists every item and every skipped item.

  1. Open AlbumRescue, allow Full Disk Access if you read a library on this Mac, click Choose a Library and pick the copy on the drive, then click Scan.
  2. Open Missing or Limited and read the reasons.
  3. If the list is empty, the copy holds what it lists. If not, go back to Step 2 on the Mac that still has access.

The scan, every list, the comparison and 5 saved photos are free. The full export is USD 34 once, for 2 Macs, with one year of updates and a 30-day refund. Download AlbumRescue and scan for free. macOS 15 or later, Mac only, works offline and uploads nothing.

What it cannot do

Questions

How do I know if my Mac has Optimize Mac Storage on? Photos, Settings, iCloud tab. The selected option is shown there.

Will Download Originals use a lot of space? It stores full-size versions on the Mac, so it can. Check free space before you start.

Can AlbumRescue download my originals from iCloud? No. It reads a library on a drive or in a backup and never talks to iCloud.

Apple, Mac, macOS, iCloud and Time Machine are trademarks of Apple Inc. AlbumRescue is made by Kayabyte and is not affiliated with or endorsed by Apple.