How to merge duplicate photos on Mac all at once

So to answer the stated question:

"No, there is not a way to merge all duplicates without having to do them one set at a time".

Tim, that's not what srbwanderer said. You missed the part about selecting multiple rows and merging them all at once.

Diane, you can do them all at once, if you select every row, but it is not necessarily a good idea. The automatic duplicate detector sometimes makes mistakes for one reason or another, so a cautious user would review the list (perhaps in small batches) before trusting the algorithm entirely.

Hello dianefromsioux falls,

As long as the Mac is running macOS 13 or later, these steps from Remove duplicate photos in Photos on Mac - Apple Support should help with removing duplicate photos:

1. In the Photos app  on your Mac, click Duplicates in the sidebar.

Note: If you’re using iCloud Shared Photo Library, click the Library pop-up menu in the toolbar, then choose Both Libraries.

2. Select the duplicates you want to merge.

You can select individual items in a single row and merge them or select multiple rows of duplicates and merge them all at once. A single original photo or video is kept from the selection in a row and other duplicates are deleted.

3. Click Merge [number] Duplicates. 

One original photo or video appears where the selected duplicates were located in your library. Deleted duplicates appear in the Recently Deleted album where you can recover or permanently delete them.

Have a good day.

As markwmsn says, you just select them all, or the ones you want, and click Merge. It happens. And as

léonie said, you need to be careful--this is my example of two pictures that Photos thinks are duplicates,

but are not at all duplicates!

I want to add that, when you hit Merge, half the pictures are deleted and replaced by the other one in all the albums either was in. But the deleted pictures don't disappear-- they go to Recently Deleted, so you have a month to change your mind.

Hello

I have multiple photo albums in my photo app, and I am worried that if I merge photos, the photo(s) will be removed from that album.

Will that be the case? Or would they remain in the album?

Thank you for the help!

When you merge two photos that are in two different albums, the merged photo will appear in both albums.

The automatic merging will only be problematic, if the photos to emerged are having different metadata, for example different capture times or different titles and captions. Photos cannot know which date and time are the ones you want to keep.