User Guide

Duplicate Detective scans your Mac for duplicate files and helps you remove them to free up disk space. This guide walks you through the entire process, from selecting folders to scan through to deleting the duplicates found.

Getting Started

When you first launch Duplicate Detective, you will see the main window where you can add folders to scan.

Click the + icon to open a Finder window, then navigate to the folder you want to scan and click Choose. You can also drag and drop folders directly into the app window.

Important: Do not drag folders from the Finder sidebar (such as Documents, Downloads, or other shortcut icons). These are shortcut references, not actual folders, and dragging them out of the sidebar will remove the shortcut regardless of where you drop it.

Once you have added the folder you want to scan, click the Start Scan button in the bottom-right corner of the window.

Scanning for Duplicates

During the scan, a progress bar and status messages will keep you informed. Scanning time depends on the number of files in the selected folder -- large folders with many files will take longer to process.

When the scan is complete, you will see a summary showing:

• The total number of files scanned
• The number of duplicates found
• The total disk space occupied by those duplicates

Click Next to proceed to the results screen, or go back to adjust your scan settings.

Reviewing and Deleting Duplicates

The results screen displays all duplicate files found during the scan. By default, you will see all file types together. You can filter by category (Folders, Images, Audio, and more) using the toolbar at the top of the window.

Use the search bar to find specific files by name. You can also sort results by Size, Type, Name, Count, or Selected in ascending or descending order.

Click on any file to see a preview in the right-hand panel. Click the magnifying glass icon to reveal the file in Finder so you can see exactly where it is located on your Mac.

There are two ways to select duplicates for removal:

• Auto-select -- Automatically marks all duplicate copies for deletion while keeping one original copy of each file. You can configure whether the oldest or newest copy is kept in Settings.
• Manual selection -- Check the boxes next to individual files to mark them for deletion.

Important: Do not check every copy of a file unless you want to remove it from your system entirely. The auto-select feature will always keep at least one copy.

Once you have made your selections, click Next to see a confirmation screen listing all files marked for deletion. Confirm to proceed, and the selected files will be moved to the Trash by default. You will then see how much disk space has been recovered.

Settings

Open Settings by pressing Cmd + , or by selecting Duplicate Detective > Settings from the menu bar.

The following options are available:

• Move to Trash -- Enabled by default. Deleted files are sent to the Trash where they can be recovered if needed. If you disable this option, files will be permanently and irreversibly deleted.
• Create aliases -- When enabled, an alias (shortcut) pointing to the original file is created at the location of each deleted duplicate.
• Auto-select mode -- Choose whether to auto-select the oldest or newest copy of each duplicate for removal.
• Minimum file size -- Set a minimum file size threshold. Only files at or above this size will be included in scans. The default is 50 KB.
• Ignored file extensions -- Specify file extensions that Duplicate Detective should skip during scans. Some common extensions are included by default, and you can add or remove entries as needed.
• Excluded folders -- Add specific folders that you do not want Duplicate Detective to scan.