Tidy and find

How to find duplicate files on a Mac

Updated 25 October 2026 · 3 min read

macOS has no duplicate finder outside Photos. Here is how to find exact duplicates with a Finder search or Terminal checksums, and how Orrel matches copies by content and sends them to the Trash after you review them.

Duplicates pile up in predictable ways: the same attachment downloaded twice, a folder copied to the desktop "just in case", photos exported more than once. Finder will not point them out, but there are reliable ways to find them.

Start with names in Finder

Most accidental copies carry a tell in their name. macOS adds " copy" or " 2" when you duplicate a file, and browsers add " (1)" when you download the same file again. In Finder press ⌘F, choose This Mac, set the first row to Name contains and type copy. Repeat with (1).

This finds likely duplicates, not certain ones. A file called "Report copy.docx" may have been edited after it was made, so open both or compare sizes before throwing one away.

Exact duplicates with Terminal

Two files are truly identical when their contents produce the same checksum. macOS includes shasum, and with a few other tools you can list every group of identical files in a folder:

find ~/Downloads -type f -size +100k -exec shasum -a 256 {} + \
  | sort \
  | awk '{ if ($1 == prev) { if (!shown) print line; print; shown = 1 } else shown = 0; prev = $1; line = $0 }'

Each line shows a checksum followed by a path; lines with the same checksum are the same file. Change ~/Downloads to another folder, or +100k to skip more small files. Checksumming a large folder reads every file, so it takes a while on big video collections.

It is accurate, but the output is a wall of hashes, and deleting from it means copying paths by hand.

Photos has its own

If the duplicates are in your Photos library rather than in Finder, open Photos and look under Utilities in the sidebar for Duplicates. Photos groups identical and near-identical shots and offers to merge them, keeping the best quality and combining their details. It only works inside the library.

Before you delete

• Keep the one in the right place. The copy inside a project folder is usually the one to keep, not the one in Downloads.
• Check for links. Some apps point at a file by its path. Removing the copy an app uses can break a project.
• Use the Trash. Moving to the Trash gives you a way back if you pick the wrong copy.

How Orrel does it

Orrel's Clean Up screen has a Duplicates list. It treats files as duplicates only when a SHA-256 hash of their contents matches, so different names do not hide a copy and matching names do not create a false one. Each group shows every location, and you tick the copies to remove. Chosen files go to the Trash, never deleted outright, so Finder's Put Back still works.

The same screen lists large files and old installers, which are often the same clutter from another angle: an installer downloaded three times shows up in both lists.

Where Orrel stops

Orrel only finds exact duplicates. Similar photos, burst shots, resized copies and a PDF saved twice with different metadata are different files as far as it is concerned. It looks at your own files in the home folder, not ~/Library, hidden folders or external drives, and it does not look inside your Photos library, where Photos' own Duplicates album is the right tool.