What's taking up space on your Mac, and how to see it

Start with Storage settings

macOS already sorts your disk into categories. Open:

Apple menu, then System Settings, then General, then Storage

The bar at the top splits your disk into Applications, Documents, Photos, iCloud Drive, Messages, macOS, System Data and so on. Move the pointer over a color to see how much space it uses. Light gray is free space. The same path works in macOS 15 Sequoia, macOS 26 Tahoe and macOS 27 Golden Gate.

Below the recommendations, each category has an Info button. Click it to see what's inside. The most useful one for this question is Documents, which covers files in your home folder that no other category claims. It has a Large Files list and a File Browser that shows how much space each folder uses (Apple).

There's one big gap. System Data has no Info button, and Apple says you can't manage the contents of that category. It's whatever is left after the named categories are counted, so it often holds local Time Machine snapshots, caches, swap files and app data in your Library.

Macintosh HD · 401 GB of 500 GB used

Example numbers

• Applications64 GB
• Documents118 GB
• Developer52 GB
• Photos41 GB
• macOS22 GB
• System Data104 GB

What’s usually inside System Data

Caches

App, browser and system caches. Most refill on their own.

Local snapshots

Time Machine keeps these on the disk until it needs the space.

Virtual memory

Swap files and the sleep image, managed by macOS.

App data

Containers and support files in your Library.

Logs

Diagnostic and crash reports.

Purgeable

Space macOS can free by itself when an app needs it.

If System Data is the large part on your Mac, read what System Data is and how to clear it.

See folder sizes in Finder

Finder can show the size of every folder, but it doesn't by default. Turn it on once and you can walk down from your home folder to whatever is big.

1. 1

   Open your home folder

   In Finder, choose Go > Home. Almost everything that's yours on the Mac is inside it.

2. 2

   Switch to list view

   Choose View > as List so each item gets a Size column.

3. 3

   Turn on folder sizes

   Choose View > Show View Options, select Calculate all sizes, then click Use as Defaults so other folders show sizes too.

4. 4

   Sort by size

   Click the Size column header until the largest item is at the top. Finder may take a moment to measure big folders.

5. 5

   Open the biggest folder and repeat

   Work down level by level until you reach files or folders you recognize.

6. 6

   Check your Library folder

   Hold the Option key and choose Go > Library. Look at Application Support, Containers, Caches and Developer, which are often the largest.

For a single folder, select it and press ⌘I (File > Get Info). The Size line shows how much space it uses.

The Library folder in your home folder is hidden because apps manage it. It's also where much of the space goes: app data, caches, Messages attachments, Xcode's simulators. Holding Option while you open the Go menu is the safe way in. If it's big, library caches on a Mac explains what each part is.

Get an exact list in Terminal

Terminal's du command measures folders the same way, only faster to read. This lists the folders in your home folder, largest first:

du -hd 1 ~ 2>/dev/null | sort -rh | head -20

What each part does:

• du -hd 1 ~ measures every folder one level inside your home folder, in readable units.
• 2>/dev/null hides the "Operation not permitted" lines for folders macOS protects.
• sort -rh | head -20 puts the largest first and shows the top 20.

To go a level deeper, put a folder in place of the ~, for example:

du -hd 1 ~/Library 2>/dev/null | sort -rh | head -20

These commands only read. They can't change or remove anything. Some folders, such as Mail and Safari data, are measured only if Terminal has Full Disk Access. That's set here, and if you turn it on for this, turn it off again afterwards:

System Settings, then Privacy & Security, then Full Disk Access

Look outside your home folder too

Most of what fills a Mac is in your home folder, but not all of it. Three other places are worth a Get Info:

• Applications, at the top of the disk. Select it in Finder and press ⌘I. Storage settings also lists every app with its size under Applications.
• Library, at the top of the disk. It holds data shared by every account: sound libraries for GarageBand and Logic Pro, printer drivers, and app data installed for all users. Choose Go > Go to Folder and type /Library.
• Users. Other accounts on the Mac keep their own home folders here. Storage settings counts them under Other Users & Shared.

To measure everything at once, this lists the top-level folders of the volume your files live on. It asks for your administrator password and only reads:

sudo du -xhd 1 /System/Volumes/Data 2>/dev/null | sort -rh | head -20

What usually takes the most space

The same few things come up on most Macs:

• Your own files. The Photos library, music, movies, and what's in Desktop, Documents and Downloads.
• App data in your Library. Application Support, Containers and Group Containers often hold more than the apps themselves: databases, offline files, downloaded media.
• Messages and Mail. Attachments in your conversations and mailboxes are stored on the Mac and add up over the years.
• iPhone and iPad backups. Each one holds a copy of a device's data. See delete old iPhone backups.
• Developer tools. Xcode build data, simulators, Android emulators, Docker disk images and node_modules folders. See why Xcode takes up so much space, Docker disk space, and the developer page.
• Single huge files. Virtual machines, local AI models, disk images and video exports. Find large files lists them.
• System Data. Local snapshots, swap and caches. See Time Machine local snapshots.

Why the numbers don't always match

Storage settings, Finder and other tools rarely agree to the gigabyte, and that's normal:

• macOS counts purgeable space as available, even though it's still on the disk. See purgeable space.
• APFS clones share space. Two copies of the same file can take the space of one, but Finder adds them up as two.
• Some folders are protected or hidden, so one tool counts them and another doesn't.
• Storage settings puts files into categories, while Finder and du count folders. The same file can land in different places.

If the gap is large and nothing explains it, when Mac storage doesn't add up goes through the causes one by one.

What's safe to remove and what isn't

Knowing what's big isn't the same as knowing what can go. A useful way to sort anything you find is to ask whether it comes back:

• Comes back on its own. Caches and logs. Removing them is safe, but apps refill them, so the space doesn't stay free for long.
• Comes back when it's needed. Build output, package manager caches, downloaded updates, device support files. Tools make them again when they need them. These are usually the best candidates.
• Doesn't come back. Your documents and photos, backups, app data in Application Support and Containers, and anything you made. Remove these only when you're sure, and only with a backup.

Never remove the Library folder itself, the System folder, or folders you can't identify. Look them up in the field guide first.

How MacClearings shows it: the Map

The Map in MacClearings draws any folder as a sunburst or a treemap, sized by the space each item really takes on disk. Scan your home folder, the whole Mac, or any folder you choose, then click a ring or a tile to zoom in. Esc or ⌘↑ zooms back out. A list beside the chart ranks what's inside by size.

What sets it apart from a plain chart is the field guide. Hover over a folder and the tooltip names it. Select it and the inspector's About this card says what it is, which app made it, whether it comes back, and what happens without it. It covers about 220 folders, from caches to simulator data. This is how it describes Application Support:

~/Library/Application Support

Application Support

What it is

Where apps keep the data they make and need: libraries, databases, downloaded content and settings.

Does it come back?

Doesn't come back

Without it

Most apps would lose their data and start as if new. Some data here, like game saves or notes, exists nowhere else.

Items the Suggestions rules found are colored by category. Everything else stays gray, so the parts you could act on stand out. The inspector also notes APFS compression, cloned files and hard links, which is where tools usually disagree.

For System Data, the Breakdown section starts from the numbers macOS reports and explains what it can, then shows what it can't see as a number instead of hiding it.

Right-click any item to Reveal in Finder, Quick Look, Copy Path, or Add to Cleanup. Nothing moves until you review the list and choose Move to Trash, and every cleanup can be undone from History. MacClearings never empties the Trash, so the space comes back when you empty it.