Duplicate files · Removing and restoring duplicates
What does "Clean all — keep the best of each" do?
Short answer: It keeps the recommended copy in every set on This Mac and moves the rest to the Recycle Vault in one confirmed step, telling you first how much will be freed. It's recoverable for about 6 months, and Undo last removal reverses the whole clean-up.
It clears the whole list on This Mac in one step: in every set it keeps the recommended copy — the one in your working folder, or the one you used or created most recently — and moves the other copies to the Recycle Vault.
Before it starts, a confirmation tells you roughly how much space will be freed. Everything removed stays recoverable for about 6 months, and Undo last removal in the Recycle Vault brings the whole clean-up back in one go.
If you've picked a different copy to keep in some sets, clean those sets individually first — Clean all always uses the recommended copy. Cloud accounts have their own Clean all … sets button.