Dupe guide

Scan just one folder for duplicates on Mac

Sometimes you only want to dedupe a single folder, not your whole Mac. Here's how to do it safely.

4 min read

You don’t want to scan your whole Mac — you just want to clean up one folder. Maybe a project directory full of asset versions, a music folder, or an export folder where you’ve been dumping the same files for months. A full-disk scan would take forever and surface stuff you don’t care about.

Two paths

The native way: Finder, sorted by size

You can get partway there with Finder’s column view and sort.

  1. Open the folder in Finder.
  2. Switch to List view (Cmd + 2).
  3. Click the Size column header to sort by size.
  4. Look for adjacent rows with identical sizes — those are duplicate candidates.
  5. Open suspected pairs in Preview or QuickLook to verify.
  6. Drag duplicates to the Trash.

The problem: two files of the same size aren’t necessarily duplicates, and Finder can’t tell you whether they actually match byte-for-byte. You’d have to use shasum in Terminal or compare contents manually for every pair, which is fine for a handful of files but not for hundreds.

The Dupe way

Dupe is happy to scan a single folder. There’s no minimum.

  1. Open Dupe.
  2. Click “Add Folder” and pick the one folder you want to scan. Don’t add anything else.
  3. Click “Scan.” Dupe hashes every file inside (including subfolders) with SHA-256.
  4. Review the duplicate groups. Each shows the full path so you can tell which copy is the “real” one.
  5. Tick the copies to remove and click “Move to Trash.”

Because you’ve scoped the scan to one folder, the results are focused — no random duplicates from elsewhere on your Mac muddying the list. And because Dupe hashes contents rather than comparing names or sizes, you can be confident that anything it flags is genuinely a duplicate.

Safety reminders for single-folder scans:

For developers especially: scanning a single project folder is a quick way to clean up assets, exports, or backups without disturbing version control. Dupe is $14.99 lifetime, no subscription.

← All Dupe tips