How to find the biggest files on your Mac

macOS ships with everything needed to answer “what is taking up my disk”, spread across four tools that nobody points you at.

1. The one-line answer

Spotlight already knows the size of every file it has indexed, so you do not have to walk the disk:

mdfind 'kMDItemFSSize > 1073741824'

Every file over one gigabyte, instantly. Change the number for a different threshold — 1073741824 is 1 GB, so 5368709120 is 5 GB.

On the machine this was written on, that returns seven results: three applications, a Docker disk image, and some video. The Docker image was 40 GB and I had completely forgotten it existed, which is the usual outcome.

To see sizes alongside the paths:

mdfind 'kMDItemFSSize > 1073741824' | xargs -I{} du -sh "{}" 2>/dev/null | sort -h

The catch: Spotlight skips anything on an excluded volume, and it does not index some system locations. For those, use du.

2. Folder by folder, with du

du walks directories and adds up what is inside, which is what you want when the space is spread across thousands of small files rather than sitting in one big one.

Start at the top of your home folder:

du -sh ~/* | sort -h

Then follow the biggest entry down. If ~/Library is the answer, as it often is:

du -sh ~/Library/* | sort -h | tail -15

-h gives human-readable sizes, -s totals each argument rather than listing everything beneath it, and sort -h orders those human-readable sizes correctly. It is slow on a full disk — a minute or two — because it genuinely reads every directory.

To include the whole disk you will need sudo, and you will want to discard the permission errors:

sudo du -sh /* 2>/dev/null | sort -h

3. Finder, for people who would rather not use Terminal

Finder’s search is more capable than it looks.

Open a new window, press Command-F, then set the location to This Mac. Change the first dropdown from “Kind” to Other…, and pick File Size from the long list. Set it to “is greater than” and enter a size.

Two things make this much more useful:

• Switch to list view and turn on the Size column, then click it to sort.
• Add a second criterion with the + button. “Last opened date is not in the last 1 year” combined with a size filter finds the large files you have also stopped using, which is a far better deletion list than size alone.

4. Storage settings, for the guided version

System Settings → General → Storage, then click the i next to any category. Applications, Documents, Music Creation and the rest each open a browsable list you can sort by size and delete from directly.

It is the friendliest option and it has two real limitations: it cannot see inside System Data, which is exactly where the mystery usually lives, and its totals are cached, so they lag behind reality by hours.

The places worth checking first

Before searching at all, four locations account for most surprises:

du -sh ~/Downloads
du -sh ~/Library/Containers
du -sh ~/Library/Application\ Support
du -sh ~/Library/Developer 2>/dev/null

Downloads accumulates installers. Containers holds sandboxed app data. Application Support holds everything else. Developer only exists if you have Xcode, in which case it is usually the largest folder on the machine by a wide margin.

Big is not the same as deletable

The point of finding large files is deciding what to remove, and size alone is a poor guide. A 40 GB video project you are still editing is not a candidate. A 12 GB installer for a macOS version you already run is.

The two questions worth asking about anything on the list: can I get it back if I am wrong, and when did I last open it. A file that is large, replaceable and untouched for a year is a safe delete. A file that is large and irreplaceable deserves an external drive, not the Trash.

Combining those two — size and last-opened date — is what CleanSpace’s Large & Old Files scan does, and it is why that list is more useful than sorting by size. But the Finder search above gets you the same answer for free, and knowing the four tools above means you are never guessing.