PHOTOS

It will depend on the kind of duplicates you are having in your Photos Library.

• Do you want to find similar photos - several photos of the same object taken in quick succession, or different versions of the same photo, imported at different times with different dates, filenames, or file format?
• Or do you want to find multiple copies of identical photos, exact duplicates?

There should not be exact duplicates in the library, as Photos is checking for duplicates when you import photos. However, Photos does not recognise files converted to a different format or new copies of the same files as duplicates.

Duplicate detectors can save a lot of work to search for exact duplicates, but when you want to remove redundant, similar photos you will have to compare the photos anyway to pick the best version. Even with exact duplicates you have to compare at least the metadata - titles, keywords etc, and check, if one of the photos has been used in a project or an album.

Some Duplicate detectors are cleaning aggressively and can damage your Photos Library badly. Apple is warning against using these tools. Using third-party apps to remove duplicate photos might damage your Photos for macOS library - Apple Support . With a dangerous duplicate detector you may lose all photos in your library.

To find exact duplicates or duplicates, that can be recognised by the filename or capture date, I can recommend Power Photos. It is safe to use, because it is using only the program interface of Photos and not modifying the Photos Library directly.

@Tony - sorry Tony, your reply did not show when I wrote my reply. This discussion is still showing with zero replies for me on the Overview page.

Hi

You must use an app designed to work with the photos library (Ie one that marks the photos or puts them in an album, and lets you review and then delete them, rather than doing the delete itself.

Do NOT use a general file duplicate finder not designed to work with the photos library. They will damage your photos library and likely cause loss of your photos.

I personally use PowerPhotos (I also use this for copying images and data between libraries)
https://www.fatcatsoftware.com/powerphotos/


Another suitable app recommended by experts here is PhotoSweeper (I have no personal experience of this one)

https://overmacs.com/

Both are paid apps. PhotoSweeper is the lowest cost and can recognise duplicates based on content, but PowerPhotos provides a lot of functionality in addition to the duplicate detection.

No problem - happens to me also.

There is always a benefit for more angles of info for the OP.