So, in theory, you should be able to scroll through your iCloud Photos and spot the duplicates that are next to each other. Then, after you manually find the duplicates, these steps will show you how to delete multiple pictures from iCloud: But thankfully, by default, it shows you your pictures in chronological order. Unfortunately, iCloud doesn’t have an easy way to view all duplicate pictures. How to remove duplicate photos from iCloud Instead, it will just modify the filename and add a number at the end. One of the frustrating things about iCloud Photos is that it won’t tell you if you’re trying to import a picture you’ve already imported. The same thing is true if you see pictures in All Photos and My Photo Stream. If a picture is in two albums and in All Photos, it only lives in one location and is simply being referenced in the albums. It’s important to note that just because you’re seeing pictures in multiple places in your Photos app, that doesn’t necessarily mean they're duplicated.

Duplicate image deleter