How To Free Up Space On Mac

Tips
1

My Mac’s storage is almost full and it’s running slower and showing constant “disk almost full” alerts. I’ve already deleted obvious large files and emptied the Trash, but the space barely changed. What are the most effective, safe ways to free up disk space on macOS without breaking anything important, and which built‑in or third‑party tools do you recommend?

2

Been there. macOS loves to hide junk. Here is what usually frees real space, in order of impact.

  1. Check what is eating space

    • Apple menu > About This Mac > Storage > Manage.
    • Look at System Data, Documents, Applications.
    • This tells you where to focus.

  2. Large files and downloads

    • In Storage > Manage, use “Reduce Clutter” > Review Files. Sort by size.
    • Delete old disk images (DMG), installers, movies, ZIPs.
    • Check Downloads folder manually. People often recover 10–50 GB there.

  3. Empty “phantom” Trash

    • External drives and USB sticks have their own Trash.
    • Reconnect any external drives you used. Empty Trash again.
    • Also check Photos app Trash: open Photos > Recently Deleted > delete all.

  4. iOS backups and device data

    • System Settings > General > iPhone & iPad Storage, or on older macOS
      iTunes > Preferences > Devices.
    • Delete old iPhone and iPad backups.
    • Some folks find 20+ GB stuck there.

  5. Messages, Mail, and attachments

    • Messages stores tons of attachments.
      Messages > Settings > General > Keep Messages > set to 30 Days or 1 Year.
      Then delete big chats.
    • Mail: Mail > Settings > Accounts. Disable “Download Attachments” or set to Recent.
      Then Mailbox > Erase Junk Mail and Erase Deleted Items.

  6. Photos and iCloud

    • If you use iCloud Photos, turn on “Optimize Mac Storage” in Photos > Settings > iCloud.
    • That keeps full res photos in iCloud and smaller versions locally.
    • Also delete big videos you do not need.

  7. Application leftovers and caches

    • Go to Finder > Go > Go to Folder. Type:
      ~/Library/Caches
      Delete contents of large app cache folders, not the Caches folder itself.
    • Check ~/Library/Application Support for old app folders you no longer use.
    • Be careful, if unsure, leave it.

  8. GarageBand, iMovie, Xcode extra content

    • These eat space.
    • GarageBand: open app > Sound Library > Delete Sound Library.
    • iMovie: delete old libraries in Movies folder.
    • Xcode: Window > Organizer. Delete old simulators and archives.

  9. Time Machine local snapshots

    • Open Terminal and run:
      tmutil listlocalsnapshots /
    • Then remove old ones with:
      sudo tmutil deletelocalsnapshots
    • If Time Machine is on, macOS keeps snapshots that can take tens of GB.

  10. Clean “System Data” bloat

  • System Data is a mix of logs, caches, snapshots, old updates.
  • Restart your Mac. That alone often drops a few GB.
  • Check /Library/Logs and ~/Library/Logs for huge log files and delete the big ones.
  • Make sure no huge “Previous Content” folders in /Library/Updates or /macOS Install Data.
  1. Browser and app caches
  • In Safari, Chrome, Firefox, clear cache and site data.
  • Some apps like Spotify store offline data. In their settings, reduce offline storage or delete downloads.
  1. Move stuff off the internal drive
  • Old photos, videos, raw camera files.
  • Move to an external drive. Then confirm they are there and delete from Mac.
  • Empty Trash after.
  1. Check for duplicate files
  • Use a trusted duplicate finder, or manually search for large folders in Finder with “File Size is greater than” filters.
  1. As a last step, reindex Spotlight
  • System Settings > Siri & Spotlight > Spotlight Privacy.
  • Add your disk, wait a minute, remove it.
  • This fixes wrong storage readings sometimes.

If, after all that, “System Data” stays huge with no clear reason and performance is bad, a clean macOS install with a manual restore of your data frees the most space. It is more work, but it often recovers tens of GB and speeds things up a lot.

3

Couple more angles you can try that build on what @sognonotturno said without rehashing the same stuff:

  1. Check what “System Data” actually is
    macOS likes to lump random junk into “System Data.” Instead of guessing, use a visual disk tool like GrandPerspective or DaisyDisk. They give a block map view so you can spot 10–40 GB hogs inside obscure folders you’d never open.
    This is often where you’ll find:

    • Old virtual machines
    • Giant log archives
    • Obsolete project folders from apps you uninstalled
    • Leftover temp files from video editors, DAWs, etc.

  2. Virtual machines & dev tools
    If you ever installed:

    • Parallels, VMware, VirtualBox
    • Docker
    • Android Studio or heavy dev environments
      they can eat tens of GB.
    • Look in ~/Parallels, ~/Virtual Machines, ~/VirtualBox VMs, ~/Library/Containers/com.docker.docker.
    • Docker: open Docker > Settings > Resources > Disk image > “Clean / Purge data.”
      These don’t always show clearly in the built‑in storage view.

  3. Cloud sync traps (Dropbox, OneDrive, Google Drive)
    If you sync with these, check:

    • Are files “available offline” that you don’t actually need locally?
    • In Dropbox / OneDrive / Drive, mark big folders as “online only” or similar.
      People sometimes keep 100+ GB synced locally by accident.
      Also make sure you don’t have two sync clients mirroring similar folders (like iCloud Drive + Dropbox with duplicated stuff).

  4. Check for hidden local libraries of creative apps
    Apps like Lightroom, Final Cut, Logic, VS Code, Steam, etc. stash big stuff in hidden spots:

    • Lightroom: look for .lrcat and “Previews.lrdata” in Pictures. Previews can be huge; you can rebuild them later if needed.
    • Final Cut / Premiere: project render files. In the app, clean render / cache files from within their own menus.
    • Steam: Library > right‑click games > uninstall ones you’re not playing. Steam libraries might not be in Applications, they’re often under /Users/Shared or an external drive you forgot.

  5. Sleepimage & hibernation file
    macOS keeps a sleepimage file in /private/var/vm roughly equal to your RAM size.

    • 16 GB RAM = ~16 GB sleepimage.
      Normally I don’t recommend deleting it manually, since the system will recreate it, but if you’re in a pinch and comfortable with Terminal, you can reclaim space temporarily. For a persistent change you’d tweak hibernation settings, but that’s more of a power‑user move and not something I’d push on everyone.

  6. Don’t over-clean caches
    I’ll actually disagree a bit with the “clear lots of caches” approach: nuking all caches can free some GB, but many apps will just rebuild them and hammer your disk again. Use a disk visualizer first and only nuke caches that are clearly monsters, like a browser or game cache that’s tens of GB.

  7. “One giant folder” approach
    Since the built-in tools can be kind of vague, another trick:

    • Open Finder
    • Go to your home folder
    • Cmd+F to search
    • Change “Kind” to “Other” > choose “File Size”
    • Set “File Size” > “is greater than” > e.g. 1 GB
      Sort by size. This surfaces stuff outside the usual suspects, like a single stray video capture file or an accidental clone of an entire project.

  8. Archive, don’t just move
    When you move stuff to an external disk, compressing first can help:

    • Select big folders > Right‑click > Compress
    • Move the resulting ZIP/Archive to external
    • Confirm it opens there, then delete the original folder on the Mac
      Some project folders shrink by 30–70% when zipped, so your external space goes further.

  9. Last resort before clean install
    Before going nuclear with a full OS reinstall like @sognonotturno mentioned, try:

    • Create a brand‑new user account
    • Log into that account and check About This Mac > Storage
      If “System Data” and used space are dramatically lower on the new account, most of your bloat is in your old user’s Library. That tells you a clean user profile plus copying only what you need might solve it, instead of wiping the whole system.

You’re not crazy if deleting big stuff seems to change nothing: macOS sometimes holds space in snapshots or caches until it feels like releasing it. After making big deletions, reboot, leave the Mac plugged in and idle for a bit, then recheck storage. Sometimes it takes a while for the numbers to settle.

4

Couple of additional angles that haven’t really been hit yet, trying not to rehash what @sognonotturno already covered.

1. Time Machine local snapshots & clones

Everyone talks about “System Data,” but a surprising chunk can be Time Machine’s local snapshots and old clones:

  • If you’ve ever cloned the disk with Carbon Copy Cloner / SuperDuper to the same drive before using an external, you might have a hidden copy.
  • Time Machine keeps local snapshots on the internal disk even if your backup drive is not connected.

Check via Terminal:

tmutil listlocalsnapshots /

If you see a ton of entries:

sudo tmutil deletelocalsnapshots 2024-02-15-123456

Repeat for old ones. Afterward, restart and recheck storage. This can suddenly free tens of GB.

I’d actually disagree with the idea that you should “just wait” for macOS to free this space. In practice, it often holds snapshots far longer than is useful on cramped drives.

2. iOS device backups & Xcode cruft

If you ever synced an iPhone/iPad or installed Xcode:

iOS backups

  • Open Finder
  • Plug in your device
  • In the sidebar, select it
  • Manage Backups
    You may see 20–40 GB of ancient backups. Delete anything for devices you no longer own or very old OS versions.

Or check manually:

~/Library/Application Support/MobileSync/Backup

Sort by size in Finder and nuke old ones.

Xcode

Xcode is a storage black hole:

  • Derived Data
  • old simulators
  • old Device Support files

In Xcode:

  • Settings > Locations > Derived Data > click arrow > delete old project folders
  • Window > Devices and Simulators > remove simulators you never use

You can also safely delete old iOS DeviceSupport folders in:

~/Library/Developer/Xcode/iOS DeviceSupport

Leave only the iOS versions you actually deploy/debug to.

3. Photos / iCloud “optimization” reality check

If you use the Photos app with iCloud:

  • Open Photos > Settings > iCloud
  • If “Download Originals to this Mac” is checked, your entire library is local. Switching to “Optimize Mac Storage” can free a lot of room, but:
    • You need steady internet.
    • Big edits on weak connections can be annoying.

Also check for:

  • Exported copies of the Photos library that you forgot in Downloads or Desktop
  • Duplicate libraries in ~/Pictures

Use Finder search:
Search “kind: package” in Pictures and look for multiple Photos Library.photoslibrary bundles.

4. Messages & attachments

Messages can silently eat storage, especially if you send a lot of photos/videos:

  • Messages > Settings
  • Keep Messages: set to 1 Year or 30 Days instead of Forever
  • In a huge conversation, click the “i” button and scroll through attachments; manually delete big ones

macOS often hides this usage under “System Data” or “Documents” but it’s really just old memes and videos.

5. Mail attachments & old mailboxes

If you use Apple Mail:

  • Mail > Settings > Accounts > uncheck “Download Attachments” or set to “Recent” instead of “All”
  • Mailbox > Erase Junk / Erase Deleted Items
  • Old mailboxes:
    ~/Library/Mail
    Sort subfolders by size. If you removed an account long ago, you may still have its entire local archive sitting there.

Be careful not to delete folders for accounts you still care about. When in doubt, archive to an external drive first.

6. Virtual audio / video plugins & content packs

Creative software often hides its real bulk in shared content folders:

Common spots:

  • /Library/Application Support
  • ~/Library/Application Support

Look for:

  • Huge sample libraries (Kontakt, Logic, Ableton packs)
  • Video effect packs, LUTs, sound effects

If you have a fast external SSD, you can often move libraries there and point the app to the new location in its settings. This gives you permanent relief instead of constant purging.

7. When “System Data” looks totally wrong

If About This Mac shows something absurd like 300 GB of System Data and none of the tools (including the nice block visualizers @sognonotturno mentioned) explain it, try:

  1. Boot to Safe Mode
    • Shut down
    • Turn on while holding Shift
    • Log in, let it sit a bit, then restart normally

Safe Mode triggers extra cleanups, caches rebuild, and sometimes breaks stuck disk snapshots.

  1. Run Disk Utility > First Aid on your main volume
    Corrupted APFS snapshots or orphaned containers can make the storage graph lie.

If neither changes the reported usage, you’re usually looking at:

  • Massive per-user Library bloat
  • Or something odd in the APFS container layout (then a proper backup + erase + reinstall is the clean fix).

8. “How To Free Up Space On Mac” tools & tradeoffs

Since you mentioned you already did the obvious manual cleanup, this is usually the point where people look for a “How To Free Up Space On Mac” style one‑click cleanup utility.

Pros of using such a tool:

  • Surfaces obscure junk locations without you spelunking through /Library
  • Safer deletion rules than random Terminal commands
  • Good for recurring maintenance instead of one big panic cleanup

Cons:

  • Can be aggressive with caches you might want to keep (e.g., offline docs, build caches)
  • Some run background daemons that consume RAM/CPU
  • You still need to understand what you’re deleting if you care about dev tools or creative workflows

I’d generally pair a cleanup app with manual double‑checking via Finder or disk visualizers rather than trusting it blindly.

9. Strategy so it does not fill right back up

Once you claw back space:

  • Set a personal minimum free space target: 15–20% of disk
  • Keep large, infrequently used assets (videos, VM images, sample libraries, Steam games) on an external SSD
  • Make regular Time Machine or clone backups before big changes, so a future “clean install” is painless instead of terrifying

If you post a screenshot of your Storage breakdown plus the size of /Users vs /System (and whether you use Time Machine, Photos, iCloud, Xcode, or VMs), people can usually pinpoint the main hog very quickly.