The following is a list of the criteria that can be used in duplicate rules to select photos from among a set of duplicates.
- Album: chooses photos based on whether they belong to one of the albums in the Photos library. This can be used in cases where you have some duplicate photos, but one instance of the photo has been added to an album, and you want to make not to remove the copy of the photo that has been added to an album. Note that this only looks at the contents of “regular” albums, not smart albums.
- Caption: if you have entered custom captions in Photos for your photos, this criterion lets you choose duplicates based on the length of that caption, or whether the caption contains a particular piece of text.
- Date: chooses based on the date the photo was taken.
- Edited: chooses based on whether the photo has been edited.
- Favorite: chooses based on whether you’ve marked the photo as a “Favorite” in Photos.
- File size: chooses either the smallest or largest file in the duplicate group. Note that for edited photos, this will use the size of the original version of the photo.
- Filename: chooses based on the length of the original photo’s filename, or whether the filename contains a piece of text that you enter. This can be handy to choose things like “IMG_1234.JPG” over “IMG_1234 (1).JPG”.
- Height & width: chooses based on the pixel dimensions of the photo. The height and width will be multiplied together and that result used to do the comparison.
- Format: allows you to prefer one format of photo over another. For example, if you have some photos for which you have both a HEIC and a JPG version, you can opt to always choose the HEIC over the JPG.
- # of keywords: chooses according to how many keywords have been assigned to each photo.
- Keyword: chooses based on whether the photo has been assigned a particular keyword that you specify.
- Library: chooses based on what library they belong to. If you are searching across multiple libraries for duplicates, this criteria can be useful if you prefer to keep photos from one library over another library.
- Live Photo: chooses based on whether a photo is a Live Photo or not (photos with their “liveness” manually disabled are not considered to be Live Photos)
- Modification date: chooses based on the date each photo was last edited.
- Place: chooses photos according to whether they have a geographic location assigned to them in Photos.
- Title: chooses based on whether the photo has been given a custom title or not. Photos assigns a default title to each photo base on the photo’s filename (e.g. “IMG_0001”), but if you have typed in your own titles for some photos, this can help preserve the photos that have those custom titles. You can also choose based on whether the title contains a particular piece of text.