How to check disk space on Mac and find what's taking it

Running low on storage is one of those problems that sneaks up on you. macOS gives you several tools to dig in — from a built-in visual breakdown to Terminal commands that pinpoint the exact folders hoarding gigabytes. Here's how to use all of them.

The quickest overview: Storage in System Settings

The fastest starting point is the built-in storage panel. On macOS Ventura (13) and later the path changed slightly — it's no longer in About This Mac.

1. Click the Apple menu in the top-left corner.
2. Choose System Settings.
3. Click General in the sidebar, then Storage.

You'll see a colour-coded bar showing how your disk is split between Applications, Documents, iCloud Drive, iOS Files, System Data, and Other. Hover over any segment for a rough number. Below the bar, Apple shows a few suggestions — things like emptying the Trash automatically, storing files in iCloud, or clearing caches. These are worth reading but not always worth acting on blindly.

The panel won't give you folder-level detail, but it tells you where to look next. If "Other" or "System Data" is unusually large, Terminal is your friend.

Check free space in one command

Open Terminal (Applications → Utilities → Terminal) and run:

# see total, used, and available space on your main volume
df -h /

The output shows your disk size, how much is used, and how much is free. The percentage in the last column is how full your drive is. If it's above 90%, you need to act.

Find the largest folders in ~/Library

The ~/Library folder is where apps silently accumulate caches, logs, saved states, and support files. It's often the biggest surprise.

# show the top 20 largest items in your Library folder
du -sh ~/Library/* | sort -rh | head -20

The output lists folder sizes in descending order. Common culprits: Application Support (app data and game saves), Caches (safe to clear for most apps), Containers (sandboxed app data), and Mail (message attachments and entire email databases if you use Apple Mail offline).

Find the largest files in Downloads

Downloads is almost always full of things you grabbed once and forgot about — disk images, old archives, video files.

# show the 10 largest items in your Downloads folder
du -sh ~/Downloads/* | sort -rh | head -10

Review what shows up. Disk images (.dmg) you already installed, ZIP archives you already extracted, and large video files you've already watched are usually safe to delete.

Sort Finder by size

You don't always need Terminal. In any Finder window, press ⌘J (or go to View → Show View Options) and set Sort By to Size. The largest files float to the top. This works in List View and is useful for quickly scanning a folder before deleting anything.

You can also use Finder's Get Info on any folder (select it, press ⌘I) to see its total size — though it can take a moment to calculate for large directories.

Go deeper with ncdu

If you want an interactive, drill-down view of your entire drive, ncdu (NCurses Disk Usage) is excellent. It's not built into macOS, but you can install it with Homebrew in one line:

# install ncdu via Homebrew (https://brew.sh)
brew install ncdu

# then scan your home folder
ncdu ~

Use the arrow keys to navigate folders and press d to delete the selected item. It's the fastest way to interactively hunt down what's wasting space, especially inside ~/Library or ~/Documents.

iCloud downloads taking up space

If you use iCloud Drive, files you've opened stay downloaded locally unless you remove them. In Finder, any file with a cloud icon next to it is not stored locally — but files without that icon are. You can right-click any file or folder in iCloud Drive and choose Remove Download to free the local copy while keeping it in iCloud.

The Storage panel in System Settings also shows how much local iCloud content you have and offers to optimise it.

What to check next

Once you've identified what's taking space, your options are: delete the files directly, use an app uninstaller to clean up leftovers, or clear app caches. If System Data in the storage bar looks unusually large, it often includes Time Machine local snapshots — these clear on their own once your drive fills up, but you can also delete old backups manually in Time Machine settings.

Checking disk space is rarely a one-time task. A quick df -h / every few months keeps surprises away.