Mac OS Ventura's Photos: Eliminating duplicate pictures

Follow these instructions:

1. In the Photos app  on your Mac, click Duplicates in the sidebar.
2. Note: If you’re using iCloud Shared Photo Library, click the Library pop-up menu in the toolbar, then choose Both Libraries.
3. Select the duplicates you want to merge.
4. You can select individual items in a single row and merge them, or select multiple rows of duplicates and merge them all at once.
5. 
6. Click Merge [number] Duplicates.
7. 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.

Hope this helps!

Well, first thing is that a 1.3mb and a 485kb version of a photo are not duplicates - they are different versions. Photos and before it, iPhoto (and most other photo apps) frequently have multiple versions of the same image. After all, think about the little thumbnail you see in the Photos window - it would be wasteful (of disk space) to have a full-sized version of the image for that use. So a smaller version is created. When you edit an image a preview is created, used for sharing to other apps and so on. So that's why you get different versions at different sizes. In this case therefore the largest file size is most likely to be the original of the image. I simply would not worry if the images have been edited or not - you can do that again is you need to.

Only you can decide what you want to do. As a rule of thumb it's fair to say that the larger version has more data to work with. That's the one I would keep.