How can I identify duplicates in my Photos Library on my Mac?

Question

Level 1

6 points

How can I identify duplicates in my Photos Library on my Mac?

I was told by Apple Care that if I see a category under Utilities labeled "Duplicates" this means Photos has found duplicates in the library. I created a new, empty library on an external drive from an export from another library on another external drive. I know it has duplicate photos because I created one before the import process started to make sure I had at least one. However, after many hours Photos does not find any duplicates. This library is less than 19 GB in size. Using M2 MacMini Pro with 32 GB of memory and Sequoia 15.1.

In the Duplicates category on the right panel there is a "Finding Duplicates..." notification which includes this: "Photos scans your library to find duplicates. Scanning will continue when you're not using the app"

More than one senior advisor in Apple Care has said that means you can't be using the app, i.e. the app is not open and there is no dot under the Photos icon in the dock in order for the process to continue.

And more than one senior advisor has said that is not correct, i.e. the process will only continue if the library is open and there is a dot under the icon.

I need to resolve this contradiction because I have many libraries to consolidate and know I have many duplicates.

Any clarification would be greatly appreciated.

[Re-Titled by Moderator]

Mac mini (M2 Pro, 2023)

Posted on Nov 3, 2024 5:25 AM

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Answer 1

Nov 4, 2024 8:22 AM in response to worx25

To find out what app is in the foreground, which one is currently active, you can use hold command-tab to get a list of all open apps (same as apps with a dot next to the icons in the dock.) The one on the left is currently active. For me, it's Safari right now, because, well, I'm typing, here. If I click on Calendar, then that will be on the left and Safari will be second from the left as the most recently used app.

For best results the computer should be plugged in, connected to the internet, running, with Photos not active. There's still some question about if it's better to have Photos open or closed. I leave it open all the time, more or less.

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Answer 2

Nov 3, 2024 6:59 AM in response to worx25

Photos needs to think that you are not using Photos, because background scanning for duplicates takes time away from other normal Photos things like editing and browsing and organizing. So Photos can't be running in the foreground.

Some people have experimented and found that Photos needs to be shut down to get the fastest scanning. Some other people (I think that I am one) have found that shutting down makes no difference from just running in the background. I know that Photos is open all the time on my Mac.

I hope you appreciate this clarification for what it's worth…

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Answer 3

worx25 Author

Level 1

6 points

Nov 3, 2024 8:48 AM in response to Richard.Taylor

Thanks very much Richard Taylor. re “…Photos can't be running in the foreground.” Do you know whether it is running in the foreground if there is a dot under the Photos icon in the Dock or if there is no dot?

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Answer 4

worx25 Author

Level 1

6 points

Nov 4, 2024 3:57 AM in response to Old Toad

Thanks Old Toad. So now I have to figure out whether if the window is not on top e.g. it is minimized or behind another window, AND there is a black dot under the icon on the Dock, the duplicate finding process is continuing in the background. So far, when the window in not on top and there is a black dot, the library I have been working on has not found the duplicate I put into it but I am going to give it some more time.

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Answer 5

léonie

Level 10

197,147 points

Nov 4, 2024 10:22 AM in response to worx25

When I want Photos to scan the library, I am starting Photos once after logging into my user account, then forget about it and do something else, like reading my mail or so.

If there is no progress at all in Photos, it could be that one of the background processes has crashed. In that case it will help to log off and on again and to restart Photos.

It will take a very long time until Photos will find the first duplicates. Photos is not just looking for exact duplicates but for similar images. It does not suffice to compare the file attributes, Photos needs to analyze each photo and to find out what it is showing. So it will have to analyze all photos before it can start to look for duplicates. For my library with 50000 photos and videos it took nearly three weeks, before the first duplicates have been shown.

You wrote: " I know it has duplicate photos because I created one before the import process started to make sure I had at least one."

Could you clarify this? Did you have two identical image files among the files you imported? or has one of the duplicate pair already been in the library? I am asking, because Photos is scanning for duplicates, when it is importing files. It will point out duplicates and ask, if we want to import a photo again, if it is already in the library. Has Photos asked about the duplicate, when you imported the photos?

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Answer 6

worx25 Author

Level 1

6 points

Nov 4, 2024 8:24 PM in response to léonie

Thanks léonie. I had a folder (Folder A) with images that were exported from a previous library. Inside Folder A were a couple of dozen sub-folders. I copied an image from one of the sub-folders and pasted it into a newly created additional sub-folder. I then imported Folder A into a new library and when that process finished I confirmed that could see the two duplicate photos in the new library. I then looked in the “Duplicates” category in Utilities and it said “Finding Duplicates…” Photos did not ask me about the duplicates when I imported Folder A.

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Answer 7

worx25 Author

Level 1

6 points

Nov 5, 2024 10:26 AM in response to léonie

Wow léonie. Almost 3 weeks until the first duplicates showed up. I am afraid to ask how long it took to find all the duplicates in this library. If this timing is an indication of how long it is going to take in my situation, I have a big problem because I have a lot of photos and libraries to consolidate and I know I have many duplicates.

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Answer 8

Old Toad

Level 10

210,443 points

Nov 5, 2024 11:11 AM in response to worx25

worx25 wrote:

Wow léonie. Almost 3 weeks until the first duplicates showed up. I know I have many duplicates.

If you would like to do it "manually" and quicker consider the following:

You want an app that will identify the potential duplicates, put them in an album or mark them with a keyword for easy retrieval and deletion by you. You don't want one that does the deletion itself for obvious reasons.

I've run tests on the these two apps with the following results and found them to be safe to use:

PowerPhotos - $29.95

PowerPhotos is the iPhoto Library Manager version for Photos and is very powerful. Although more expensive I would recommend it as it has more capabilities than the others like the capability to merge Photos libraries or copy photos, both original and edited versions, along with their metadata between libraries.

PhotoSweeper - $9.99 - Demo version available.

PhotoSweeper compares bitmaps and/or histograms so it can detect duplicate images even if they have different file sizes, file names, image sizes and capture dates.

Just some more food for thought.

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Answer 9

worx25 Author

Level 1

6 points

Nov 5, 2024 11:25 AM in response to Old Toad

Interesting. I am going to try both. Thanks. Do you know whether when I try these apps it is possible to stop the Photos duplicate finding process in order to conserve cpu processing capacity and prevent any possible conflicts?

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Answer 10

Old Toad

Level 10

210,443 points

Nov 3, 2024 9:29 AM in response to worx25

If Photos is running in the foreground its window will be on top of any other windows. In the background the Photos window will no be visible.

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Answer 11

Old Toad

Level 10

210,443 points

Nov 4, 2024 9:24 AM in response to worx25

Just click on the desktop and all open apps will be in the background with the Finder in the foreground.

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Answer 12

worx25 Author

Level 1

6 points

Nov 4, 2024 7:29 PM in response to Old Toad

Old Toad: Thanks for that tip.

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Answer 13

Old Toad

Level 10

210,443 points

Nov 5, 2024 10:03 AM in response to worx25

You're welcome.

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Answer 14

Old Toad

Level 10

210,443 points

Nov 5, 2024 1:57 PM in response to worx25

You can't stop Photos from searching for duplicates but there will be no conflict as results are all virtual, i.e. pointers to the original files that are viewed in an album.

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