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Mac

Mac storage full: 'System Data' taking space

Mac storage full or 'System Data' huge? Safe ways to free space: Storage settings, old iPhone backups, Trash, and Time Machine snapshots.

Difficulty
Easy
Time
15-30 min
Steps
6
Updated

Sounds like this?

  • 'Your disk is almost full'
  • System Data or Other uses many GB
  • Can't install macOS updates

Step by step

  1. Apple menu › System Settings › General › Storage. Wait for the bar to finish calculating.
  2. Click the (i) next to each category. Review Documents for large files, and Applications for unused apps.
  3. Delete old iPhone/iPad backups: Finder › select your device › Manage Backups (or in Storage under iOS Files).
  4. Turn on Optimize Storage and Empty Trash Automatically if you want them.
  5. Restart the Mac. System Data often shrinks after a restart as caches and temporary snapshots clear.
  6. If you use Time Machine, plug in the backup disk and let a backup finish. Local snapshots are removed when space is needed.

Related error codes & messages

Quick answers

When should I stop and get professional help with "Mac storage full: 'System Data' taking space"?

Stop and get help if: System Data keeps growing by many GB a day. You can't free enough space for macOS updates. Ask about external storage or a bigger Mac. Boise Computer Care can diagnose it for a $60 fee; call 208-996-3508.

How long does this fix take and how hard is it?

Plan on 15-30 min. Difficulty: Easy.

Is it safe to try this myself?

Mostly, if you follow these precautions: Never delete files in /System or /Library by hand. Before deleting iPhone backups, confirm you have an iCloud or newer backup.

Which error messages or codes does this guide cover?

Your disk is almost full, System Data.

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