Suggest the best tools/Apps for detecting and removing duplicates (deduping) photos

I'm hoping some experienced users can help me avoid massive amounts of work deduping.

I have the same photo (many times with the same file name, but not always) on multiple drives... from multiple phones, downloaded to multiple laptops, backed up to multiple external drives.

I now have a network and server with enough storage to merge all drives... but need to find an easy way to merge all photos from the last 20 years and depup them so there is only one representation of each photo.

What are the best tools/Apps for detecting and removing duplicates (deduping) photos?