Duplicate File Finder - FAQ

Duplicate File Finder can scan your Mac’s internal drive, external USB or NAS drives, and Photos libraries. It doesn’t scan files stored only in the cloud (iCloud, Google Drive, Google Photos) unless they’re saved locally on your Mac.

Duplicate folders contain absolutely identical content - every file and subfolder matches exactly. Similar folders share some files in common, but each folder also contains files that do not exist in the other. Think of duplicate folders as perfect clones and similar folders as diverged copies.

Duplicate Photos: These are binary-identical files. They have the same resolution, size, and metadata.

Similar Photos: These are visually similar images (e.g., burst shots, slightly different angles, or edited versions). Our app groups them together so you can choose the best shot and remove the redundant ones.

Yes. You can filter duplicate search results by file name. Type the name into the search field, and the app instantly filters the duplicate list to show only matching results.

Yes. By default macOS hides certain system and user folders, but Duplicate File Finder can scan them too. To enable this, go to Settings and turn on the Scan Hidden Folders option.

Yes. Duplicate File Finder can scan any readable drive connected to your Mac, including external hard drives, USB flash drives, SD cards, and network-attached storage. Simply add the external drive as a scan location and run the scan. Read more >>

Sort the list of duplicates by file size. The app will arrange duplicate groups by their total size, so the files wasting the most disk space appear at the top. This is the fastest way to recover storage on your Mac - target the biggest groups first.

When you use the Select by folder feature to compare specific folders, outside duplicates are the copies located in folders other than your target folder. This distinction helps you decide which copy to keep and which to remove.

You can skip any folder using the Skip List. Go to Duplicate File Finder Settings from the menu bar, choose the Skip List tab, and add the folders you want to exclude. Those folders will be ignored in all future scans.

Yes. Go to Settings → Skip List and add individual files or file extensions you want to exclude. This is useful for ignoring system files, project templates, or placeholder files that appear as duplicates but should not be removed.

Enable the Remove Empty Folders option in Settings. When active, the app will automatically remove any folders that become empty after you delete duplicate files - keeping your folder structure clean without extra manual steps.

Yes. You can merge folders in two ways, depending on your goal:

• Merge multiple folders: Use the dedicated tab in the left sidebar to combine several different folders into one master destination.
• Merge similar folders: Click the Merge Folders button within the “Similar Folders” results to unify directories with overlapping content. Read more >>

Merging intelligently combines unique files from both locations into one folder, eliminating redundancy while ensuring no data is lost.

Smart Select automatically marks duplicates that contain words like “copy,” “copy 2,” or “copy of” in their file name - names that macOS creates by default when you duplicate a file in Finder. You can customize the Smart Select rules in Settings, making it easy to bulk-select obvious copies for removal.

All duplicate files are technically identical in size, type, and binary data - there is no built-in way to determine which came first. File names may differ, but content is the same. Duplicate File Finder displays all copies so you can review them and decide which ones to keep. We recommend keeping the file in your most logical or frequently accessed location.

By default, removed files are moved to the Trash, not permanently deleted. This gives you a safety net to recover files if needed. If you want to permanently delete duplicates immediately (bypassing the Trash), go to Settings → Remove tab and change the removal method.

Yes, but this option is disabled by default to protect against accidental data loss. To enable it, go to Settings → Advanced tab and turn on Allow Removing All Duplicate Copies. Please, use this option with care.

There are three ways to select duplicates within a specific folder:

1. Right-click on any duplicate in the results list and choose “Select All Copies in this Folder.” This selects all duplicates in that folder only, without touching subfolders.
2. Go to Settings → Smart Select tab → add the folder to the Always Select list. Then click Smart Select to automatically target those folders. Read more >>
3. Use the Select by folder feature for a guided folder-by-folder comparison. Read more >>

Yes. Open the context menu on any duplicate file and use the command “Add to Always Select List” or “Add to Never Select List.” You can also manage duplicate folders in the settings → Smart Select tab. Read more >>

This error means macOS is preventing the app from moving files to the Trash. The most common causes are:

• The file is being used by another program.
• You don’t have the necessary user account permission to remove it. To get the permission, switch to Finder, select the file and use the “Get Info” command from the context menu or by using the Cmd+I key shortcut. Change the file permission in the Sharing & Permissions category.
  If you are scanning external storage, then the reasons for the message might be.
• Your external drive does not have a Trash bin yet. A Trash bin for external storage is created when you remove a file via Finder. So to resolve this issue, you should remove any one file on the external storage in Finder.
• Your disk is connected to your external storage as read-only. This could happen, for example, if you have connected your disk with NTFS and don’t have a driver to write to NTFS. You should therefore install the necessary extension to allow the removal of the duplicates.

Yes. Go to Menu Bar → Duplicate → Restore removed duplicate → select the files you want to restore, and click Restore. Removed files are sent to the Trash by default, so they can also be recovered directly from the Trash as long as it has not been emptied.

This depends on where you purchased the app:

• Website version (nektony.com): one license per Mac computer
• App Store version (Pro or Free with In-App Purchase): up to 5 Mac computers sharing the same Apple ID, plus additional Macs via Apple Family Sharing

Open Duplicate File Finder, then open the Upgrade to Pro window and click the Restore button. This re-links your App Store purchase to the current installation without needing a license key.

Please note that the App Store edition of Duplicate File Finder doesn’t support license keys purchased from the website. To activate the Pro version with the license purchased from the website, do the following:

1. Close and delete the App Store edition of Duplicate File Finder.
2. Download the site edition of the app from this link.
3. Install the site edition of the app.
4. Open the app and click the Unlock Full Version button.
5. Click Enter License Key in the appeared window.
6. Copy your License Key.
7. The key will be activated automatically.

Your license key is sent automatically to your registered email address right after purchase. If you do not see it:

• Check your Junk or Spam folder.
• If you paid with PayPal, check the email address registered with your PayPal account.
• If you entered an incorrect email at checkout, contact support at support@nektony.com - the team will locate your order and resend the key.

If you purchased the app from the App Store, follow these steps:

1. Open the App Store.
2. Tap your name in the bottom left corner → go to Account Settings.
3. Scroll down and locate Subscriptions.
4. Click Manage.
5. Select Duplicate File Finder from the list of purchased apps and click to cancel your subscription.

If you purchased the app from our website, do the following:

1. Log in to your PayProGlobal account.
2. Click Subscription in the left panel.
3. Locate Duplicate File Finder and click to cancel the subscription.

Yes. Previous versions of the website (non-App Store) edition are available on the Nektony website. Note that only the site version is available as a legacy download; older App Store versions cannot be downloaded outside of Apple’s standard update mechanism.

Follow these steps to manually uninstall the app:

1. Quit Duplicate File Finder.
2. Go to the Applications folder → remove Duplicate File Finder to Trash.
3. In the Finder’s menu bar, click Go → Go to Folder → in the window that appears, type ~/Library, and hit Go.
4. Within the Library folder, find and remove Duplicate File Finder service files. Note, depending on the version of the app you use, you will need to find and remove different folders.

If you downloaded the free version of the app from the App Store, find and remove the following files:

• ~/Library/Application Scripts/com.nektony.Duplicates-Finder
• ~/Library/Containers/com.nektony.Duplicates-Finder

If you purchased the PRO version of the app on the App Store, find and remove these files:

• ~/Library/Application Scripts/com.nektony.Duplicates-Expert
• ~/Library/Containers/com.nektony.Duplicates-Expert

If you downloaded the app from the site, find and remove these files:

• ~/Library/Application Scripts/com.nektony.Duplicate-File-Finder-SII
• ~/Library/Application Support/com.nektony.Duplicate-File-Finder-SII
• ~/Library/Caches/com.nektony.Duplicate-File-Finder-SII
• ~/Library/Preferences/com.nektony.Duplicate-File-Finder-SII.plist

After removing all service files, empty your Trash to complete the uninstallation.