Any search criteria/filter/logic to search 2 folders for files that are NOT duplicates?

[jono]

Is there any search criteria/filter/logic to search 2 folders for files that are NOT duplicates and/or to search for files that are only in one of the folders?

For example, I have like a dozen hard drives with files and photos (including many duplicates) that I'm trying to consolidate into a new NAS. I'd like to plug in a drive, scan it to identify any files that are NOT already on the NAS, and then copy just those ones over. Is there any way to do this?

I know one (dirty) workaround would be to search the drive for duplicates, delete those duplicates from the drive, and then copy anything remaining to the NAS. However, I'd prefer a non-destructive method if possible.

Also, a forum post about this from 2010 said this was not possible at that time, but I figured I'd ask just in case this functionality was added sometime in the last 15 years.

I love this software - thanks!

[Administrator]

Scan the NAS and external drive for duplicates using the search option "Show only files without duplicates at the search result".