Did not find all duplicates
It’s just OK. In my library of 11,000 photos, it identifed 49 duplicates in photos and videos. I know there are more because I can manually walk through the photo library and see them - most remaining duplicates are video files which I understand are a little harder to identifiy as duplicates because a lot of video files lack metadata for comparison. It’s worth trying this first, then switch to manual duplicate removal.
Have fun…
Fat-Banana_ about
Photos Duplicate Cleaner, v1.6.3