Duplicate Finder

Overview

The Duplicate Finder tool scans your Mac for duplicate files and folders. It identifies exact matches based on their SHA-1 hash, allowing you to easily select and delete duplicates to reclaim disk space.

Adding Folders to Scan

1. Select Duplicate Finder from the sidebar.
2. Click the Start button on the welcome screen.
3. Click Add Folder and choose a folder from the Folder Select window, then click Choose.
4. To compare duplicates between folders, add multiple folders to the scan list before starting.

You can also drag and drop folders directly into the Duplicate Finder window.

Do not drag folders from the Finder sidebar (such as Documents or Desktop shortcuts). Dragging a sidebar shortcut away from the Finder window removes that shortcut. Instead, navigate to the actual folder in Finder and drag it from there.

Running a Scan

1. After adding your folders, click the Start Scan button in the bottom-right corner.
2. A progress bar near the top of the window shows the scan's progress. Larger folders with many files will take longer to scan.

Reviewing Results

Once the scan is complete, your duplicate files are displayed in a list. By default, you see the All file types view.

• Use the category tabs at the top (Folders, Images, Docs, Video, Audio, etc.) to filter by file type.
• Use the search bar to find a specific file by name.
• Sort results by Size, Type, Name, Count, or Selected in ascending or descending order.
• Click any file to see a preview in the right-hand panel.
• Click the magnifying glass icon to reveal the file's location in Finder.

Deleting Duplicates

1. Tick the duplicate files you want to remove, or click the Auto Select button to automatically mark all duplicates while keeping one copy of each file.
2. Click the Next button to review your selections on a confirmation screen.
3. Confirm the deletion. By default, deleted files are moved to the Trash.

A summary screen shows how much space was freed up. You can then quit the app or start a new scan.

Do not tick all copies of a file for removal unless you want to delete it entirely. The Auto Select button keeps one copy and marks only the duplicates.

Settings

Open preferences by pressing Cmd + , or by choosing Disk Aid > Settings from the menu bar.

Under the Duplicate Finder section, you can configure the following:

• Move to Trash -- When enabled (default), deleted files are sent to the Trash. When disabled, files are permanently and irreversibly deleted.
• Create alias -- When enabled, a shortcut pointing to the original file is created when a duplicate is deleted.
• Minimum file size -- Set a minimum file size so Duplicate Finder only scans files of that size or larger.
• Ignore file extensions -- Specify file extensions that Duplicate Finder should skip during scans.
• Ignore folders -- Add specific folders that Duplicate Finder should not scan.