Finding duplicate and large forgotten files

Start with large files

Large files are the quickest win. Deleting one forgotten 20 GB screen recording does more than an afternoon of sorting photos. The usual suspects:

• Screen recordings and exported videos on the Desktop or in Movies
• Disk images (.dmg) and installers (.pkg) in Downloads
• Zip archives you unpacked once and forgot
• Virtual machines and their snapshots
• iMovie and Final Cut Pro libraries, including render files
• Old iPhone and iPad backups (see where iPhone backups go)

In Storage settings

Choose Apple menu > System Settings, then General, then Storage. Click the Info button next to Documents. The Large Files view lists your biggest files, wherever they are in your Home folder, with their size and when you last opened them. Downloads does the same for your Downloads folder. Select a file and click Delete, or Show in Finder to look at it first.

This is the easiest place to start, but it shows files only, not folders, and leaves out what belongs to other categories such as Photos.

In Finder

Finder can search by size, which catches files Storage settings files under other categories:

1. In a Finder window, press Command-F.
2. Click This Mac to search everywhere.
3. Change the first menu to Other, choose File Size and click OK.
4. Set it to is greater than 1 GB.
5. Click the plus button to add Last opened date is before a date a year ago, if you want only forgotten files.

Switch to List view and sort by Size. To keep the search, click Save; it becomes a Smart Folder in the sidebar that updates on its own.

To see which folders are large, open your Home folder in List view, choose View > Show View Options and turn on Calculate all sizes.

In Terminal

Spotlight can answer the same question from Terminal. This lists files over 1 GB in your Home folder:

~ % mdfind -onlyin ~ 'kMDItemFSSize > 1000000000'
/Users/you/Movies/Screen Recording 2025-03-11.mov
/Users/you/Downloads/Xcode_16.xip
/Users/you/Parallels/Windows 11.pvm

Spotlight finds only what it has indexed. For a complete pass, find reads the disk itself. It is slower but misses nothing you can read:

~ % find ~ -xdev -type f -size +1G 2>/dev/null

Both commands go by a file’s full size. Files in iCloud Drive or other cloud folders that are online only show up too, although they take no space on your Mac.

Look for forgotten folders too

Some of the largest items are folders, not files: an old project, a copy of a camera card, a folder of exports. Storage settings does not show those, and a size search does not find them, because each file inside is small.

The du command lists the size of every folder one level down, so you can drill in step by step:

~ % du -sh ~/* 2>/dev/null | sort -h | tail -8
 18G  /Users/you/Pictures
 41G  /Users/you/Movies
 77G  /Users/you/Documents

Repeat with the largest folder, for example du -sh ~/Documents/*, until you find what is taking the space. The guide to the du command explains it in more detail.

Duplicates: what counts as a copy

A real duplicate has exactly the same content, byte for byte, even if the name or date differs. Files with the same name are not necessarily duplicates, and duplicates often have different names, such as IMG_2041.jpg and IMG_2041 copy.jpg.

The common causes:

• Downloading the same attachment more than once
• Importing photos from a camera card twice
• Copying a folder as a backup and never removing it
• Moving to a new cloud service and keeping the old folder

APFS clones take no extra space

On the startup disk, a copy you make in Finder (File > Duplicate, or Option-dragging within the same disk) is usually an APFS clone. The copy and the original share their storage until one of them changes. Finder shows both at full size, but together they use the space of one.

That is why deleting a cloned copy frees almost nothing. A duplicate finder that does not know about clones overstates how much you will get back.

Built in tools for photos and music

For photos and music, use the app itself, because it keeps its library in order:

• Photos. In the sidebar, under Utilities, open Duplicates. Photos groups identical and near identical pictures, and Merge keeps the best version with the combined metadata.
• Music. Choose File > Library > Show Duplicate Items. Hold Option to change it to Show Exact Duplicate Items, which matches more strictly.

Everything else

For documents, videos and downloads, compare before deleting:

1. Sort the folder by size in List view. Real duplicates have exactly the same size, down to the byte (Get Info shows it).
2. Open both with Quick Look (select and press Space) to confirm they match.
3. Keep the copy in the place you would look for it, and move the other to the Trash.

If a file is in a cloud folder and shows a cloud icon, it is online only and takes no space on your Mac. Removing it there removes it from the cloud too.

Decide, then empty the Trash

Large files are often large for a reason: a client’s raw footage, the only recording of a family event. Before you delete, ask whether you have another copy. For files you want to keep but rarely use, an external drive is the better home.

Move what you remove to the Trash and empty it once you are sure. The space is freed only then.