How to free up disk space on a Mac

A full Mac is almost never a mystery once you look in the right order: Storage settings, Trash, Downloads, unused apps, caches, then the System Data bucket macOS will not explain. This is the practical sequence that recovers space without guessing.

By Diljit PR · Published 3 September 2026

1. Check storage in System Settings

Do not delete anything until you know where the space went. The Storage pane is the map; everything else on this page is how to act on what it shows.

1. Open the Apple menu → System Settings.
2. Click General in the sidebar, then Storage.
3. Wait for the coloured bar to finish calculating — it can take a minute or two on a large disk.
4. Note which categories are large: Applications, Documents, Photos, Mail, and the grey System Data block on the right.

Two patterns are almost universal. First, the named categories are often smaller than you expect. Second, System Data is frequently the largest block on a Mac that is more than a year old, and macOS gives you no button to clear it. If your free space is low and Documents looks fine, System Data is usually the answer — see what System Data actually is.

Older macOS versions called this category Other. It is the same bucket under a different name. On macOS Monterey and earlier the path was About This Mac → Storage → Manage; the categories and the problem are unchanged.

2. Empty the Trash

Deleted files still occupy disk space until the Trash is emptied. Storage settings count them; Finder's free-space number ignores them until they are gone. Right-click the Trash in the Dock and choose Empty Trash, or open it and click Empty in the toolbar.

If you prefer not to do this by hand, turn on Empty Trash Automatically in System Settings → General → Storage. macOS then removes items that have sat in the Trash for more than 30 days. It is a sensible default; it is not a substitute for emptying when you need space today.

3. Clear Downloads and large files

Downloads is the folder most people never tidy. Installers, exported videos, ZIP archives and one-off PDFs accumulate for years. Open Finder → Go → Downloads, then switch to List view and sort by Size.

• Old installers. Files ending in .dmg or .pkg for software you have already installed are safe to delete. On the Mac we measured they alone were 1.86 GB.
• Duplicate downloads. Lecture slides, shared ZIPs and browser saves often appear as file.pdf, file (1).pdf and file (2).pdf. Keep one; remove the copies.
• Large media. Screen recordings, exported movies and raw camera dumps belong on an external drive or in cloud storage once you are done editing them.

Storage settings also lists Documents with a size breakdown. Use it to find oversized folders, then decide whether each file is still worth keeping on the internal SSD. Moving a 20 GB video project to an external drive frees the same space as deleting it, without the risk.

4. Uninstall apps you no longer use

Unused apps are an obvious target, but dragging one to the Trash only removes the application bundle. Preferences, caches, containers and saved state stay in your Library folder indefinitely — including for apps you removed years ago. Over time those leftovers become part of System Data.

The complete method is covered in our guide to uninstalling apps on a Mac completely: quit the app, remove it from Applications, empty the Trash, then clear its leftovers from the eight Library folders macOS never cleans. Match on the bundle identifier (com.vendor.appname), not the display name, or you will miss most of them — and risk deleting a sibling app's data if you match too loosely.

App Store apps can also be removed from Launchpad (click and hold until the icon jiggles, then click the delete badge). Apps installed from a developer's website will not show that badge; use Finder. For a dedicated tool that lists every removable app with its real on-disk size and leftover paths, see the Mac uninstaller overview.

On the machine measured for this site, a single code editor left behind 1.86 GB — nearly twice the size of the app itself — after a normal Trash delete.

5. Clear caches safely

Caches are local copies apps keep so they load faster next time. They are designed to be regenerated, which makes them the safest large thing to delete on any Mac — as long as you clear the right folders.

The short version: quit your apps, open Finder → Go → Go to Folder (⇧⌘G), go to ~/Library/Caches, and delete the contents of the folders inside, not the folders themselves. Then empty the Trash. Full steps, browser-specific instructions, and the two folders you must never touch are in how to clear cache on a Mac.

Application caches alone held 22.5 GB on the Mac we measured; system caches another 6.0 GB. Browser caches are often the largest single slice inside that total — Chrome's cache on the same machine was 13.5 GB, separate from bookmarks and logins, which clearing cache does not remove.

6. Shrink System Data

System Data is the catch-all category macOS uses for files it cannot file under Apps, Photos, Documents, Music or Mail. It is not one thing and it is not a bug. In practice it is caches, logs, local Time Machine snapshots, old iOS backups, disk images, virtual machine data, and support folders belonging to apps you deleted long ago.

You cannot delete "System Data" as a label. You shrink it by removing the safe things inside it. After Trash, Downloads and unused apps, the highest-return moves are:

1. Old iPhone or iPad backups. Check ~/Library/Application Support/MobileSync/Backup. A single local backup can exceed 100 GB, and iCloud Backup usually makes it redundant.
2. Caches and package manager leftovers — covered above, and often the largest regenerable slice.
3. App leftovers from programs you already removed.
4. Time Machine local snapshots. macOS creates these when the backup drive is offline and counts them as System Data. They are purgeable, but macOS is conservative about reclaiming them. Thinning with tmutil thinlocalsnapshots / 21474836480 4 in Terminal forces the issue; it needs an administrator password.

For the full breakdown of what lives in the grey bar and what is safe to remove, read What is System Data on a Mac?. The important rule: never try to delete a folder literally named System Data, and never clear anything under /System itself. "System" (roughly 10–15 GB) is macOS; "System Data" is the unsorted remainder.

7. Photos, Messages and iCloud Optimise

Media and chat history are the large categories Storage settings does name. They are also the ones where a careless delete is expensive, so treat them after the regenerable junk above.

Photos

Open the Photos app and review Recently Deleted — items sit there for 30 days and still count against the library size. If your library is mostly synced through iCloud Photos, turn on Optimise Mac Storage in System Settings → Apple Account → iCloud → Photos (wording varies slightly by macOS version). Full-resolution originals stay in iCloud; the Mac keeps smaller versions and downloads the original when you open a photo. That is the built-in way to reclaim tens of gigabytes without deleting anything permanently.

If you are not using iCloud Photos, the reliable space win is to move the Photos library to an external drive (Photos → Settings → General → Show in Finder, then move the .photoslibrary package and double-click it on the new volume to reopen). Do not delete the library until Photos has opened successfully from the new location.

Messages

Messages attachments — especially videos and Live Photos — grow without an obvious ceiling. In Messages → Settings → iMessage, enable Keep Messages: 30 Days or 1 Year if you do not need forever history on this Mac. To reclaim space immediately, open a conversation, choose View → Attachments, and delete large items you no longer need. Empty the Trash afterwards if macOS moved them there.

iCloud Drive and Optimise Storage

In System Settings → General → Storage, Store in iCloud keeps Desktop and Documents in iCloud and can leave lighter placeholders on the Mac. Optimise Storage removes watched films and TV shows automatically. Both are useful on a small SSD; neither clears caches, leftovers or developer folders. Use them as background policy, not as the whole cleanup.

8. When a Mac cleaner helps (and when it does not)

Manual cleanup is enough when the problem is Trash, Downloads or a handful of large files you can see. It stops being realistic when the space is spread across Library caches, leftover support folders, package-manager downloads, duplicate files and project dependency trees — the categories Storage settings collapses into System Data without paths.

A good Mac cleaner earns its keep by showing those paths before anything is removed, matching leftovers on bundle identifiers rather than partial names, and moving files to the Trash instead of erasing them outright. A bad one inflates the number with language packs, sleep images or system caches you should not touch, or charges a subscription for a task most people do a few times a year.

Broomkit is built for that middle ground: the scan and Disk Map are free with no size cap, Reclaim and the uninstaller unlock with a one-time licence, and every file is listed with its full path first. If you are comparing options — especially against subscription cleaners — the CleanMyMac alternative comparison covers pricing models, free tiers and what each tool actually shows before deletion.

A cleaner does not replace emptying the Trash or deciding which photo library you still need. Use it after the visible steps, for the invisible remainder.

9. Measured example: 84.8 GB on one Mac

These numbers come from one full scan on macOS 26, on a 994 GB disk, on 30 August 2026. They are not estimates. Your breakdown will differ; the pattern — a few regenerable categories dominating the total — holds on most machines that feel "full" despite an empty Desktop.

Add the major rows and you are already past 80 GB before counting smaller categories. None of these appear as a single clickable item in System Settings → Storage. That is why a Mac can report almost no free space while Documents looks tidy: the space is real, but it is filed under System Data or scattered across Library paths Storage will not open.

If you write code, notice the top row. Dependency folders and package caches together were 46.4 GB on this machine — more than Photos on many Macs — and almost every general "free up space" checklist skips them. Deleting a finished project's node_modules (or equivalent) is safe; reinstalling recreates it. Old Xcode simulators and unused Docker images are the same idea: regenerable working data counted as System Data until you prune them.

A practical order that usually works

1. Check System Settings → General → Storage and note System Data versus Documents.
2. Empty the Trash.
3. Sort Downloads by size; remove old installers and obvious duplicates.
4. Uninstall apps you no longer use, including Library leftovers.
5. Clear ~/Library/Caches and browser caches — never /System/Library/Caches.
6. Shrink System Data: iOS backups, leftovers, then snapshots if needed.
7. Optimise Photos and Messages; turn on iCloud storage recommendations if they fit how you work.
8. Run a free scan for whatever the manual steps missed, then decide whether a one-time cleaner is worth it for your Mac.

Keep roughly 10–15% of the disk free. macOS uses free space for memory swap, local snapshots and updates; a Mac that is 98% full feels slow long before it refuses to save a file. On a 256 GB MacBook Air that buffer is only a few tens of gigabytes, which is why the same habits that are optional on a 1 TB desktop become urgent on a soldered laptop SSD.

Related guides

Sources: Apple — Free up storage space on your Mac · Apple — Uninstall apps on Mac · Uninstall apps · Clear cache · System Data · CleanMyMac alternatives · Mac uninstaller. Published 3 September 2026. Measurements taken on macOS 26, 994 GB disk.