Duplicate Finder groups files that match the tool’s comparison criteria. It helps reduce redundant copies, but it cannot determine which location is most meaningful to you.
Configure the scan
Open Settings → Scanning → Duplicate Files to review the minimum file size. A larger threshold focuses on files with greater storage impact; a smaller threshold increases the number of files and scan time.
Scan for duplicates
- Open Files → Duplicate Files Finder.
- Select the folder or folders to scan.
- Avoid overlapping selections when possible.
- Start the scan.
- Wait for comparison to finish before making selections.
Choose copies to keep
In every group, preserve at least one verified copy. Prefer a copy that:
- Lives in the expected project or library.
- Has the ownership and permissions you need.
- Is referenced by an application or workflow.
- Exists on reliable storage.
- Is included in your backup.
Understand the available actions
Each file in a duplicate group can have one of these actions:
- Primary File: preserve this file as the group’s reference copy. Other files in the group can then be removed or replaced with Finder aliases.
- Keep: leave this file unchanged.
- Remove: include this duplicate in the removal confirmation.
- Alias: remove the duplicate and create a Finder alias at its original location that points to the Primary File.
An alias is a small Finder reference, not another copy of the file. It can help preserve a familiar path for manual navigation, but it is not a substitute for the original file and may not satisfy software that expects a real file at that path.
Use Smart Select carefully
Smart Select keeps the most recently modified file in each group and selects the other copies for removal. It does not create aliases.
Modification date alone cannot identify the most important copy. Review each group when file location, project references, tags, ownership, or backup purpose matters.
Review the removal method
Open the confirmation window and review Move to Trash before proceeding. For personal-file tools, diCleaner initially enables moving items to Trash and remembers the choice for that module.
If Move to Trash is turned off, selected files are deleted directly and cannot be restored from Trash. Alias actions use the same removal choice before creating the Finder alias.
Two identical file contents can have different paths, names, dates, tags, or project roles. Do not remove a copy solely because its bytes match another file.
Do not automatically prefer the newest date: copying an older file can give it a newer creation date. A copy on a backup or archive disk also serves a different purpose from two working copies on the same disk.
Managed libraries and backups
Be cautious inside Photos libraries, music libraries, application bundles, Time Machine data, package contents, source-control internals, and virtual machines. Their owning software may require a specific internal structure.
After removal
If files were moved to Trash, verify the result before emptying Trash. If aliases were created, test the workflows that used the original locations and confirm they work with Finder aliases.
Open the project or application that used the files and confirm that it still works. Run a new duplicate scan to see the current state rather than relying on the previous group.