To find out what's taking up space on your Mac, start in System Settings › General › Storage, which sorts your disk into categories. Then follow the largest category down into Finder, one folder at a time, with every folder's size showing.
On most Macs, a handful of things account for most of the used space, and a few minutes of following the numbers finds them.
The usual answers are a Photos library, iPhone backups, Messages attachments, old downloads and videos, apps and their data, and on a developer's Mac, build files, containers and AI models. Which of them it is differs on every Mac, which is why it's worth looking rather than guessing.
Some space doesn't sit in any folder you can open. Time Machine's local snapshots, swap files and folders macOS keeps private all take room that Finder can't show. When the folders you find don't add up to the used space, that's usually where the rest is.
This post shows how to look with the tools already on your Mac, folder by folder, where the space usually turns out to be, and what to do once you've found it.
What's taking up space on your Mac? Start with Storage settings
Storage settings is the quickest overview. It won't show every folder, but it tells you which kind of thing to look for, and it lets you act on several categories directly.
How do you open Storage settings?
In macOS 27 Golden Gate, choose Apple menu › System Settings, click General in the sidebar, then click Storage. macOS Tahoe 26 is the same, and so is every version back to Ventura. Before Ventura, choose Apple menu › About This Mac, then click Storage.
Give it a minute to finish counting. The bar at the top fills in as macOS works out each category, and the numbers can move while it does. The post on how to check storage on a Mac explains each number it shows.
Which category is the biggest?
Each category in the list below the bar shows its size. Note the three largest. On most Macs one or two of them hold far more than the rest, and they tell you where to go next.
A category with an Info button opens a list of its largest items, where you can select one and click Delete, or click Show in Finder to look at it first. Apple singles out Applications, Documents, Messages, Music Creation, Podcasts, Trash and TV as the ones worth opening.
Use Documents' File Browser
The Info button next to Documents has buttons for large files and for downloads, and a third, File Browser. File Browser shows the folders in your file system with how much each one holds, so you can open the largest and keep going down.
Apple notes that folders already counted in another category appear dimmed there. That's a useful hint: a dimmed folder's space shows up under Photos, Messages or another category instead.
What Storage settings can't show
macOS and System Data have no Info button. Apple describes System Data as files that don't fit the other categories: logs, caches, virtual memory files and other files the system uses, plus app support files and plug-ins. You can't open it from Storage settings.
If System Data is one of your largest categories, the folder-by-folder search in Finder is how to see inside it. The post on what System Data is takes it apart piece by piece.
| Largest category | What it usually means | Where to look next |
|---|---|---|
| Documents | Videos, downloads, disk images, project folders | File Browser, or Finder sorted by size |
| Photos | Your Photos library | Photos' own settings |
| iOS Files | Backups of iPhones and iPads | Its Info button |
| Messages | Attachments in conversations | Its Info button, or Messages |
| Applications | Large apps, often games or creative suites | Its Info button |
| System Data | Caches, snapshots, app data, developer files | Finder, starting in your Library folder |
What about other accounts and other volumes?
If other people have accounts on this Mac, their files count against the same disk, under Other Users in Storage settings. You can't open their folders from your account, so ask them to look from theirs.
Click All Volumes in Storage settings to see every volume and how full each is. Volumes in one container share its free space, so a second volume you added to the internal disk can be the one taking it.
Follow the space folder by folder in Finder
Finder can show every folder's size, sorted largest first. Starting at your home folder and opening the largest folder each time, you reach the culprit in a few clicks.
How do you see folder sizes in Finder?
Adding up folder sizes takes time, so Finder doesn't do it in list view until you ask. Open a folder, choose View › as List, then choose View › Show View Options and select Calculate all sizes.
Then click the Size column heading to put the largest items first. Finder works the sizes out in the background, so large folders can take a moment to fill in.
To keep this setting for other folders, click Use as Defaults in the same options window. Apple's guide to Finder views covers the other options there.
Where should you start?
Start with your home folder, the one with the house icon in the Finder sidebar. Almost everything you can act on lives there: your files, and the Library folder where apps keep theirs.
- Open your home folder in list view with sizes calculated.
- Sort by size and open the largest folder.
- Repeat inside it. A few levels down, the culprit usually has a name you recognize.
- When a folder's size stops making sense, select it and choose File › Get Info for a single, settled figure.
How do you open the Library folder?
Finder hides the Library folder. In Finder, open the Go menu, press and hold the Option key, and choose Library. Or choose Go › Go to Folder, type ~/ and press Return.
Inside it, the largest folders are usually Application Support, Containers, Group Containers, Caches and, on a developer's Mac, Developer. Each holds one folder per app, named after the app or its identifier, such as com.developer.appname.
How do you open hidden folders in your home folder?
Command-line tools often keep their data in folders whose names start with a dot, such as .ollama for Ollama's models or .gradle for Gradle's caches. Finder hides these too.
To open one, choose Go › Go to Folder and type its path, such as ~/. Sizes and Get Info work there as anywhere else.
Find large files with a Finder search
Following folders finds big folders. A search finds big files, wherever they are, including single videos and disk images buried several levels down.
How do you search for files by size?
- In Finder, choose File › Find.
- Under the search field, choose This Mac as the place to search.
- Click the first pop-up menu in the criteria row and choose Other….
- Select File Size in the list of attributes, then click OK.
- Set the row to is greater than a size you choose, such as 1 GB.
Finder lists every file over that size. Choose View › as List and sort by Size to see the largest first. Select a result and choose Show in Enclosing Folder to open the folder it's in.
Add when you last opened it
Click the + button to add a second criterion: choose Other…, then Last opened date, and set it to is before a date a year or more ago. Large files you haven't opened in a year are the best candidates to move or remove.
To appear, a file must match every criterion. Hold the Option key as you click the + button, and you can choose whether Any, All or None of the criteria must match.
Save it as a Smart Folder
Click Save below the search field, give it a name and select Add To Sidebar. The Smart Folder runs the search again each time you open it, so it keeps a live list of large files.
What a search misses
Finder's search is built on Spotlight, so folders you've excluded in Spotlight's settings are left out. It also leaves out system files and invisible files unless you add the System files and File visibility attributes, from the same list, to include them.
That's why a search and a folder-by-folder walk complement each other. Use the search for large single files, and the folder walk for folders made of many small ones, such as caches.
| Tool | Good at | What it can't show |
|---|---|---|
| Storage settings | Categories, and acting on several directly | What's inside System Data |
| Finder list view with sizes | Folder by folder, anywhere you can open | Snapshots and folders you can't read |
| Finder search by File Size | Large single files | Folders of small files; unindexed places |
| Get Info | One settled figure for one item | The rest of the disk |
| Disk Utility | Used, purgeable and free for each volume | Anything about folders |
| A disk space analyzer | The whole disk as one map | Only what macOS lets it read |
Where the space usually is, folder by folder
Every Mac is different, but the large folders turn up in the same places. Here is where to look, and what each one is.
In your home folder
Downloads collects installers, archives and files you saved once. Movies holds screen recordings, exported videos and video app libraries. Desktop and Documents hold your work, and sometimes old project folders, disk images and archives.
Pictures holds the Photos library and Music holds the Music library. Each library is a single package that its app manages, so the size you see is the library's; manage it in Photos or Music, never by opening it.
In the Library folder
Application Support holds data apps manage for you: game libraries, chat histories, virtual machines, iPhone backups in its MobileSync folder, and the leftovers of apps you've removed. It's often the largest folder in Library.
Containers and Group Containers hold sandboxed apps' data, which can include large mail, chat or media stores. Caches holds data apps can rebuild. Messages holds attachments, and Mail holds your downloaded mail.
On a developer's Mac
Developer holds Xcode's build files, simulators, device support files and archives, often the largest folder on the Mac. Docker Desktop keeps its disk image in its container, and package managers keep caches in Caches or in dot folders in your home folder.
Local AI models are the other big one: Ollama's in ~/, Hugging Face's in ~/, and LM Studio's in its own folder. A handful of models can take tens of gigabytes.
Inside apps' own libraries
Some apps keep everything in one large package or folder of their own. A Final Cut Pro or iMovie library holds the media you imported plus render files the app made from it. Virtual machines from Parallels Desktop or UTM are packages holding a whole computer's disk. Steam keeps installed games in its folder in Application Support.
Finder shows each as one item with one size, which makes them easy to spot and easy to misjudge. Manage them in their apps: Final Cut and iMovie can delete their own render files, Parallels and UTM remove machines from their own windows, and Steam uninstalls games from its Library.
DaVinci Resolve keeps its render cache outside the project instead, in a folder called CacheClip, and deletes it from its own Playback menu.
Outside your home folder
Applications holds your apps, including any full macOS installer you downloaded and didn't run. / holds data apps share between users, such as GarageBand's sound library, and / holds other people's home folders and any archived accounts in Deleted Users.
| Where | What's usually large there | How to recognize it |
|---|---|---|
~/Downloads | Installers, archives, one-off files | .dmg, .pkg and .zip files |
~/Movies | Screen recordings and exported video | Large .mov and .mp4 files |
~/Pictures | The Photos library | One package named Photos Library |
~/Library/Application Support | App data, games, iPhone backups | Folders named after apps |
~/Library/Containers | Sandboxed apps' data | Folders named with identifiers |
~/Library/Developer | Xcode's builds, simulators and archives | Xcode and CoreSimulator folders |
~/.ollama, ~/.cache | Local AI models | Model files of several gigabytes |
/Applications | Large apps and macOS installers | Install macOS apps |
- Photos library10–500 GB · Managed by macOS
- Steam games10–300 GB · Review first
- iPhone and iPad backups10–200 GB · Review first
- Local AI models20–150 GB · Review first
- Messages attachments5–100 GB · Review first
- Xcode DerivedData5–100 GB · Safe
- Docker Desktop's disk10–100 GB · Usually safe
- App caches2–30 GB · Safe
Typical ranges on Macs that have these items at all, from the research behind the app's catalog. Most Macs have only a few of them, and many have far less.
When the folders don't add up
Sometimes you add up every large folder and still come up well short of the used space. The rest is real, but it isn't in a folder you can open. These are the usual places.
Time Machine's local snapshots
If you back up with Time Machine, your Mac keeps snapshots on its own disk: one about every hour, each kept for 24 hours, plus one of your last successful backup and one before each macOS update. A snapshot holds on to files you've changed or deleted since it was taken, and no folder shows that space.
To see them, open Disk Utility, choose View › Show APFS Snapshots, and select your startup disk's volume. Your Mac counts their space as available, and Time Machine removes them as they age or when space is needed.
Folders you can't read
Some folders are closed to you or to the app you're using. Other people's home folders can't be opened from your account. Mail, Messages and some other apps keep data that macOS lets an app read only with Full Disk Access, in System Settings › Privacy & Security.
Finder itself can open your own folders. A third-party app without Full Disk Access can't measure them all, so its totals come up short. A good one tells you which folders it couldn't read.
Swap, the sleep image and other volumes
When apps need more memory than your Mac has, macOS moves some of it to swap files on the startup disk, and it can save memory to a sleep image. They live in a volume of their own, so you won't find them in your folders. Restarting clears the swap files.
Copies that share space, and files that overstate it
On Apple's file system, a copy made on the same disk can be a clone that shares the original's space until one of them changes. Adding up file sizes counts each copy in full, so folders can add up to more than the space they really take.
Some files claim to be larger than they are. Docker Desktop's disk image is the best-known: Docker says other tools may show its maximum size rather than the space it really uses. A file like that can make a folder look far larger than it is.
Is the Trash still holding it?
Items in the Trash keep their space until it's emptied, and the Trash is a hidden folder, so a folder walk can miss it. Storage settings lists it as its own category. Each external drive keeps its own Trash too, which counts against that drive until you empty the Trash with the drive connected.
Purgeable space
Finder shows available space, which includes purgeable space: caches, snapshots and iCloud downloads that macOS has agreed to remove when something needs the room. Apple separates the two: free space is open space on the disk, and available space adds what macOS can free.
To see both, open Disk Utility, select your startup disk's volume, and click the Info button in the toolbar.
| What's hiding | Why no folder shows it | Where to see it |
|---|---|---|
| Local snapshots | They're part of the file system, not folders | Disk Utility, Show APFS Snapshots |
| Other users' files | You can't open their folders | Storage settings, Other Users |
| Apps' private data | macOS keeps it from other apps | An app with Full Disk Access |
| Swap and sleep image | They're on a separate volume | Activity Monitor's Swap Used |
| Purgeable space | It's counted as available | Disk Utility's Info |
Three common answers, worked through
What you do next depends on what you found. Here is how the search usually goes on three kinds of Mac.
When Photos or Documents is the biggest
If Photos leads, the space is your Photos library. Open Photos rather than Finder. With iCloud Photos, turning on Optimize Mac Storage keeps smaller versions on the Mac and the originals in iCloud. Without it, the library can move to an external drive.
If Documents leads, open its Info button and look at its large files, or run the Finder search above. Old screen recordings, exported videos and disk images from finished projects are the usual finds. Copy the ones you want to keep to an external drive before removing them.
When System Data is the biggest
Start in Disk Utility with View › Show APFS Snapshots. If there are many snapshots and you recently deleted something large, they may be holding it; Time Machine removes them as they age.
Then open your Library folder in list view with sizes calculated. Application Support, Containers and Caches are where most of the rest is, along with Developer on a developer's Mac. Restarting also clears swap, which counts here.
When iOS Files, Messages or Applications is the biggest
iOS Files means backups of iPhones and iPads, plus their software files. Open its Info button: backups of devices you no longer have are the usual finds.
Messages means attachments. Its Info button lists the largest, and you can delete them there or in Messages. Applications usually means a few large apps, often games or creative suites, plus a forgotten macOS installer.
When space disappeared suddenly
Sometimes the question isn't what's large, but what changed. A Mac that had room yesterday and is full today usually has one new thing to blame, and a few searches find it.
Search for large files made recently
In Finder, choose File › Find and search This Mac, as above. Add two criteria: File Size set to is greater than 500 MB, and Created date set to is within last 7 days.
The results are large files that appeared this week, wherever they are. Swap Created date for Last modified date to also catch files that grew, such as a virtual machine's disk or a video project you've been working on.
Check Downloads by date added
Open Downloads in list view. If there's no Date Added column, Control-click any column heading and choose it. Sort by it to see what arrived most recently, with sizes alongside.
A single large download, such as a game, a disk image or an installer, is a common cause of a sudden drop. So is an archive that expanded next to itself, leaving two copies.
Did macOS or an app just update?
macOS saves a Time Machine local snapshot before it installs an update, and Software Update can download updates in the background, depending on its settings. Both take space for a while. macOS clears staged updates when space is needed, and Time Machine removes snapshots as they age.
Apps update themselves too. Developer tools are the biggest example: a new version of Xcode can bring new simulator runtimes, and each is several gigabytes.
Did a device or a library sync?
Each time an iPhone or iPad backs up to this Mac, its backup in your Library folder is updated. Turning on iCloud Photos, Messages in iCloud or iCloud Drive on a new Mac can download much of what's already in iCloud.
In Photos, Download Originals to this Mac keeps every full-size photo on the Mac, while Optimize Mac Storage keeps smaller versions when space is limited. Switching from the second to the first can bring down a whole library.
Is it still growing?
Open Storage settings, note the categories, and look again an hour later. A category that keeps growing points to something still downloading or syncing. Let it finish, or pause it in the app doing it, before you start removing things.
Disk space analyzers: the whole disk at once
Finder answers the question one folder at a time. A disk space analyzer reads the whole disk once and draws it as a map, so the largest folders stand out at a glance. Several exist for the Mac, free and paid.
What does a disk space analyzer show?
Most draw the disk as a treemap, rectangles sized by the space each folder takes, or as a sunburst of rings around the center. Click into a folder and the map redraws for it. The good ones also list what they couldn't read.
They don't change anything by looking. Reading names, sizes and dates is all a disk map needs.
How is an analyzer different from Storage settings?
Storage settings sorts the disk by kind: photos, documents, apps, System Data. An analyzer sorts it by place: this folder, then the folders inside it. The two answer different questions, and each fills a gap the other leaves.
Storage settings can count what no folder shows, such as snapshots, inside System Data. An analyzer can show only the files it reads, but it shows every one of them, including the folders that make up System Data.
What should you look for in one?
- It reads, and nothing else, until you ask. Measuring should never move or delete anything.
- It says what it couldn't see. A tool that quietly skips private folders gives you numbers that are too low.
- It counts shared space once. Clones and hard links counted twice make folders look larger than they are.
- It tells you what a folder is. A size alone doesn't say whether a folder is a cache or your only copy of something.
Should you give an analyzer Full Disk Access?
Only if you want it to measure everything. Without it, an analyzer can't read Mail, Messages and some other apps' data, and macOS asks before it reads Desktop, Documents and Downloads. You can grant it, and take it back, in System Settings › Privacy & Security › Full Disk Access.
What to do with what you find
Finding the space is the easy part. Deciding what to remove takes one more question for each large item: will it come back by itself, or is it the only copy?
Decide item by item
Caches, logs and build files come back by themselves, so they're safe to clear with their app closed. Installers, apps and models can be downloaded again. Videos, backups and archives may be your only copy, so they need a copy elsewhere first.
The post on what's safe to delete on a Mac goes through each folder and the right way to clear it.
Use the right place to remove it
| What you found | Where to remove it |
|---|---|
| A Photos library | Photos: Optimize Mac Storage, or move the library |
| iPhone backups | Storage settings, iOS Files |
| Messages attachments | Messages, or Storage settings |
| App caches | Finder, with the app closed |
| An app and its leftovers | The app's uninstaller, or the Trash |
| iCloud Drive files | Finder: Remove Download, not Delete |
| Xcode's simulators and runtimes | Xcode |
| Docker images and AI models | Docker Desktop, Ollama or LM Studio |
Move what you want to keep
Large things you want to keep don't have to stay on the startup disk. Copy finished projects, old videos and archives to an external drive, open the copies to check them, then remove the originals.
Some apps can move their own data. Photos can open a library from an external drive formatted as APFS or Mac OS Extended, and Docker Desktop can keep its disk image elsewhere, chosen under Disk image location in its settings. Move these through the app, never by dragging their files in Finder.
Watch what grows
One look tells you what's large today. What fills a disk next is usually what's growing: snapshots, caches, backups and attachments all grow without you saving anything.
Look at Storage settings every month or two and compare its three largest categories with last time. A category that has jumped is where to look first.
How the app does it
Wombit is a native Mac app that shows what's using your Mac's storage, explains every item in plain language, and clears it safely: Trash first, undoable and logged. It scans the whole disk or any folder at about 240,000 items a second on an M4 Pro, reading only names, sizes and dates.
The map is the home screen: a treemap and a sunburst, with a list and search. Select anything to see what it is, how safe it is to remove and what removing it costs, with a Move to Trash or Clean Up button.
Explanations come from a catalog written and checked by hand, with sources. Items no rule explains get a Best guess, written on your Mac by Apple Intelligence and labelled as a guess.
System Data, explained splits that one number into named buckets, and shows how much it couldn't explain. Folders macOS didn't let it read are listed, not skipped. Hard links and APFS clones count once, so folders add up the way macOS counts space.
Items the catalog knows get a level. Safe items, such as app caches and Xcode's DerivedData, start checked, and only they count in the headline number. Review first items, such as backups, attachments and large old files, wait for you, and Managed by macOS items, such as snapshots and the Photos library, are explained and never moved.
Scanning, the map, the explanations, System Data explained and the space meter are free, and file names and paths never leave your Mac. Cleanup and What Changed, which shows what grew since the last scan, are PRO: one payment of $4.99 with lifetime access.
Every Pro tool's review is free to open, so you see what would go and why before you buy.
Frequently asked questions
How do I see what is taking up space on my Mac?
Open System Settings, click General, then Storage, and note the largest categories. Then open Finder in list view, turn on Calculate all sizes in View Options, and sort your home folder by size. Open the largest folder each time until you reach something you recognize.
How do I see folder sizes on a Mac?
In a Finder window, choose View, then as List, then View, then Show View Options, and select Calculate all sizes. Click the Size column heading to sort the largest first. For one folder, select it and choose File, then Get Info.
Why is my Mac storage full when I don't have many files?
Much of what fills a Mac isn't saved by you: Time Machine's local snapshots, caches, iPhone backups, Messages attachments and app data all grow on their own. Snapshots don't appear in any folder, so check Disk Utility's View menu for Show APFS Snapshots.
How do I find the largest files on my Mac?
In Finder, choose File, then Find, and search This Mac. Add the File Size attribute from Other and set it to greater than 1 GB, then sort the results by size. Adding Last opened date narrows it to large files you haven't used in a while.
Why don't my folder sizes add up to the used space?
Some space isn't in any folder you can open: local snapshots, swap files on their own volume, other users' files and apps' private data. Folders can also add up to more than they take, because copies on Apple's file system can share space and some files report their maximum size.
How do I find hidden folders that take up space on a Mac?
Hold Option and choose Go, then Library, to open your Library folder, where apps keep their data. Folders that start with a dot, such as those of command-line tools and AI models, open with Go, then Go to Folder, and a path such as ~/.ollama.
Is it safe to use a disk space analyzer on a Mac?
Measuring is safe: an analyzer only needs to read names, sizes and dates. Look for one that says which folders it couldn't read and counts shared space once. Give it Full Disk Access only if you want it to measure Mail, Messages and other private app data.