How to Find Duplicate Files on Mac (Photos, Videos, and Folders)

Duplicate files are one of the most frustrating sources of wasted space. You might import the same photo twice, download the same PDF from email, or copy a folder without realizing it already exists elsewhere.

This article explains two different notions of “duplicate,” where to look first, and how NythyCleaner helps find visually similar photos and videos—not only exact byte matches.

Two Kinds of Duplicates

Exact duplicates (same bytes)

Two files are identical if they have the same size and cryptographic hash (or byte-for-byte comparison). This is reliable for documents, ZIP files, and installers.

Similar media (not identical)

Photos and videos can be “duplicates” in everyday language even when they are not the same file: resized exports, cropped screenshots, or HEIC vs JPEG copies. Hashing alone will miss those.

NythyCleaner’s Duplicate Finder uses Vision feature prints to group visually similar images and videos so you can review and delete extras without hunting folder by folder.

Where Duplicates Hide on macOS

High-yield folders to scan:

• Photos library exports — multiple exports of the same album.
• Downloads — repeated downloads of the same attachment.
• Desktop and Documents — drag-and-drop copies of the same files.
• External drives — backups copied onto the Mac without deduplication.
• Cloud sync folders — iCloud Drive or Dropbox with conflicted copies.

For a full disk overview before you delete anything, use the Disk Space treemap to see which folders dominate.

Manual Approaches (Limited)

• Finder: Sort by size and name in a single folder—works for obvious duplicates, not across drives.
• Terminal: fdupes or similar tools can find exact duplicates by hash; they do not understand visual similarity.

Use NythyCleaner’s Duplicate Finder

1. Choose volumes or folders you want to scan.
2. Start a scan. The app groups similar media using Vision.
3. Review groups before deletion—keep the best resolution or the copy in the right album.
4. Delete or move extras in bulk when you are confident.

Always keep backups of important libraries before large deletions.

How This Fits Your Cleanup Workflow

• Pair with freeing up disk space on Mac for caches and large files.
• If iCloud is tight, read iCloud Drive cleanup.

Summary

Finding duplicates on Mac is faster when you match the tool to the problem: exact deduplication for archives, visual similarity for photo libraries—and NythyCleaner focuses on the latter with a clear review step before anything is removed.