Mac storage basics · System Data and the storage categories

How do I reduce System Data on my Mac safely?

Short answer: Restart, release local snapshots, clear rebuildable app caches, remove old device backups and clean developer data. Don't delete files in system folders by hand.

You can't delete System Data as a whole, but you can shrink its biggest parts safely. Work from least risky to most:

  1. Restart — clears swap and many temporary files.
  2. Release local snapshots if you've recently deleted or moved a lot (see local snapshots).
  3. Clear app caches from apps that rebuild them (browsers, chat and editor apps).
  4. Remove old iPhone backups and leftover update files.
  5. Clean developer data with each tool's own cleanup command.

Avoid deleting anything inside /System or random Library folders by hand.

Storage Studio's Free Up Space and What's Using Space do steps 2–5 with a review first and keep anything they remove recoverable in the Recycle Vault. See freeing up space.

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