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The CoreSpotlight folder: the second Spotlight index, and what to do when it grows huge

Apps hand macOS their own searchable data, and it lands in your Library, not the main Spotlight index. How to measure it, and how to reset it safely.

5 min read

Spotlight has two indexes. The one most guides mention is .Spotlight-V100 at the top of each disk, which indexes your files. The other is in your own Library, at ~/Library/Metadata/CoreSpotlight, and it holds what apps hand to Spotlight themselves: mail messages, notes, messages, and items from third party apps.

Measure it

du -sh ~/Library/Metadata/CoreSpotlight
du -sh ~/Library/Metadata/CoreSpotlight/* 2>/dev/null | sort -h | tail

On most Macs it is well under a gigabyte. On some, after a macOS update or with a very large mailbox, it has been reported far larger, and it can keep growing while the corespotlightd process runs at high CPU. Because it lives in your Library, Storage settings counts it as System Data, not as part of any app.

Is it safe to remove?

Yes. It is an index, not your data. Your mail, notes and messages live elsewhere. If it is removed, macOS creates a new one and apps donate their items again, so searching for mail or notes in Spotlight may be incomplete for a while.

  1. Quit Mail, Notes, Messages and any app you use heavily.
  2. Open Finder, press Command Shift G, and go to ~/Library/Metadata/.
  3. Move the CoreSpotlight folder to the Trash.
  4. Restart, then empty the Trash once you are happy everything works.

Moving it to the Trash rather than deleting it outright means you can put it back if anything looks wrong.

If it grows back to the same size

  • Check the index is not fed by an app you could leave out of Spotlight: System Settings, Spotlight, then untick categories you never search.
  • A very large mailbox makes a large index. Archiving old mail helps both, see Mail attachments taking up space.
  • If it returns to tens of gigabytes after a reset, that is a fault worth reporting to Apple through Feedback Assistant.

For the main file index, see Spotlight index taking up space.

Common questions

What is the CoreSpotlight folder on a Mac?

It is a per user search index at ~/Library/Metadata/CoreSpotlight that holds items apps donate to Spotlight, such as mail, notes and messages. It is separate from the main .Spotlight-V100 file index.

Is it safe to delete the CoreSpotlight folder?

Yes. It is an index, not your data, and macOS rebuilds it after a restart. Spotlight results for mail and notes may be incomplete until it has caught up.

Why is CoreSpotlight so large?

Usually a very large mailbox or a fault after a macOS update makes the index grow. Resetting it and leaving unused categories out of Spotlight usually brings it back down.

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