Remove duplicate photos in Photos on Mac

nilesk wrote:

upgraded to OS 14.7.5. Made no difference

Okay, and is the following a potential factor here, with emphasis added: “Duplicates appear automatically in the Duplicates album in the sidebar. (Depending on the size of your library, duplicates may take some time to appear as Photos analyzes your photos.)”

nilesk wrote: Having upgraded to OS 14.7.5 it took overnight before test duplicates appeared in a "duplicates" folder. So it finally worked, thx for the help.

It's a good sign that this happened so quickly. To show these duplicates, Photos had to compare its scans of the new pictures against scans of all the others, so you know that all the pictures in the Library have been scanned.

Scanning occurs when the computer is not trying to conserve battery power; when internet is stable; and when it's not being used for other things-- plugged in, turned on, Photos not in front, and left alone is best. (Sounds good for me, too!)

nilesk wrote:

That doesn't make sense: the "duplicates" folder is available going back to OS Ventura, and I'm running Sonoma 14.1.1, i.e. a later OS.

Update from macOS 14.1.1 to macOS 14.7.5, and check again.

Wouldn’t be the first time an issue was introduced and then fixed.

Or the first time an update incidentally un-wedged something that had gotten stuck.

Please update from macOS 14.1 to macOS 14.7.5, and check again.

This is how it is supposed to work: Remove duplicate photos in Photos on Mac - Apple Support

In Sonoma the duplicates folder is here:

If you don't have a duplicates folder, then Photos hasn't found any duplicates, yet.