What is corespotlightd on Mac?

What corespotlightd does

Apps can push items into Spotlight with Apple’s Core Spotlight framework (CSSearchableIndex). Mail donates messages, Messages donates conversations, Notes and Reminders donate their items, and many third-party apps (note-taking apps, chat clients, password managers, Things, Bear and so on) donate their content too. corespotlightd receives those items, stores them in a per-app index, and answers queries for them.

It runs as your user from /System/Library/Frameworks/CoreServices.framework/.../Metadata.framework/Versions/A/Support/corespotlightd. File indexing is handled separately by mds_stores and mdworker_shared.

Why it uses CPU and memory

• First sync of a big account: a new Mac, a new Mail account, or turning on Messages in iCloud pulls down tens of thousands of items.
• A chatty third-party app: an app that re-donates its whole database on every launch, or on every small change.
• After a macOS update: per-app indexes may be rebuilt.
• Rich content: messages with attachments and Live Text in images add extra processing.

How to make it calm down

Let the first sync finish with the Mac plugged in and awake. After that it should idle near 0%.

If it doesn’t, find which app is feeding it. This streams corespotlightd’s log for a minute and shows the bundle IDs it mentions:

/usr/bin/log stream --process corespotlightd --style compact | grep -oE '[a-z]+\.[a-zA-Z0-9.-]+' | sort | uniq -c | sort -rn | head

Then:

1. Untick categories you don’t search in System Settings › Spotlight (Sonoma: Siri & Spotlight).
2. Update or reinstall the app that keeps showing up; many of these loops are app bugs.
3. For Mail, quit Mail while indexing runs; a rebuild of a mailbox (Mailbox › Rebuild) sometimes clears a stuck index.
4. Restart. corespotlightd usually behaves after a fresh start.

When to worry

It should run as your own user, from the CoreServices path. Verify:

ps -o user,pid,command -p $(pgrep -x corespotlightd)
codesign -dv --verbose=2 "$(ps -o comm= -p $(pgrep -x corespotlightd))"

Authority=Software Signing means Apple. Memory that climbs past 1 GB and never comes down is a leak rather than an attack; restarting clears it, and a macOS update often fixes it for good.

Seeing it in Stat Space

Stat Space keeps CPU and memory history for 30 days, so you can see whether corespotlightd’s busy spell is a one-off after setup or a daily pattern. In the Apps tab, its process inspector shows signer, user and parent, and the built-in dictionary explains what it is in one line. statspace whatis corespotlightd gives the same answer from Terminal.