How to delete all files in one folder that are the same as in another folder I have two folders containing videos: the first contains videos that are already referenced within Aperture, and the second contains a mix of duplicates as well as videos that are NOT already in Aperture. What I'd like to do is have the second folder contain ONLY files that are not already in Aperture (so that I can add them). How can I relatively easily delete the duplicate files in the second folder? I've been playing around with Deltopia's DeltaWalker, but it doesn't appear able to allow me to delete the duplicate files easily.
Gemini will let you do this.

Open the app, go to Preferences → Auto Select and add the path of the folder that you want to keep the files to the Never Select list.



Then, add the folders to the scan list and press Scan. Once it's complete, you can press Auto Select to automatically mark the duplicates, then delete them.