Dopp

How It Works

Dopp scans the folders you choose using SHA-256 content hashing — so it catches identical files even when they have different names or timestamps. Files are grouped by identical content, and you review each group before anything is deleted.

Nothing happens automatically. You decide what to keep and what goes to the Trash.

Review Before You Delete

Every duplicate group shows you all the copies side by side:

• Full file path, modification date, and file size for each copy
• Quick Look preview with a single click (or press Space, just like Finder)
• Mark each file as Keep or Trash individually
• Reset any group back to undecided at any time

Sort groups by most space wasted, largest file, or most copies. Filter the list to show only undecided groups or ones ready to process.

Bulk Decisions

When you trust the folder order you added, use bulk actions to pre-fill decisions across all groups at once:

• Keep First, Trash Rest — marks the copy from your first-added folder as Keep
• Keep Newest — keeps the most recently modified file in each group
• Keep Oldest — keeps the earliest file in each group
• Clear All Decisions — start over from scratch

Safe by Design

• Files go to the Trash — not permanently deleted
• Full undo: one tap restores the last batch of trashed files to their original locations
• Dopp only accesses folders you explicitly open — no access to anything else on your Mac
• No cloud uploads. No account. Your files never leave your machine.

Native and Fast

Dopp is a native Mac app built with SwiftUI. Scanning uses concurrent SHA-256 hashing across up to 8 threads, with a size pre-filter that skips files that can't possibly be duplicates before any hashing begins. A 100 GB photo library scans in seconds to minutes, not hours.

Designed for macOS. Feels like it belongs there.