macOS process library
What is mds_stores on Mac?
mds_stores is the part of Spotlight that maintains the search index on each indexed disk. When files are added or changed, mdworker processes read them, and mds_stores writes what they find into the index kept in a hidden .Spotlight-V100 folder.
- Part of
- Spotlight, the search built into macOS.
- Safe?
- Yes. It is part of Spotlight and ships with macOS.
- Can I quit it?
- You can, but macOS starts it again and indexing carries on, so it rarely helps.
The short answer
A busy mds_stores almost always means Spotlight has a lot of new material to index: a macOS update, a newly connected drive, a big copy, or a folder full of constantly changing files. It usually settles once that work is done. Rebuild the index only if search results are actually wrong.
Normal use
What mds_stores usually looks like.
Most of the time mds_stores idles with little CPU and a few hundred megabytes of memory. Brief spikes after you save, download, or unzip files are expected.
After a macOS upgrade or when you connect a large external drive, it can stay busy for an hour or more while Spotlight catches up. On Apple silicon Macs, Spotlight indexing runs mostly on the efficiency cores, so it often affects what you’re doing less than the percentage suggests.
Why mds_stores uses so much CPU or memory
- A macOS update
Major updates can trigger reindexing of your startup disk, which keeps mds_stores and
mdworkerbusy for a while afterward. - A new or external drive
Spotlight indexes newly connected volumes. A large external drive full of files is a lot of new material.
- Time Machine backups
Backup disks are indexed too, so a big backup can bring a burst of indexing with it.
- Folders that change constantly
Dependency installs, build output, and large downloads create or rewrite thousands of files. Each change gives Spotlight more to process.
How to calm mds_stores down
Start at the top. Each step is more disruptive than the one before.
- Let it finish
Keep your Mac awake and on power for a while. Indexing after an update or a new drive usually completes on its own.
- Check what Spotlight is doing
In Terminal, run
mdutil -s /to see whether indexing is enabled for your startup disk. - Exclude folders you never search
In System Settings → Spotlight (or Siri & Spotlight), click Search Privacy and add build folders, large archives, or a backup drive. Spotlight stops indexing them.
- Rebuild the index from Settings
If search results are wrong, add your disk to Search Privacy, wait a few seconds, then remove it. Spotlight reindexes it from scratch, which takes time.
- Rebuild from Terminal
As an alternative,
sudo mdutil -E /erases and rebuilds the index for your startup disk. Use it only when the index is clearly damaged.
Seeing it in Spare
Find what it’s reacting to.
Spotlight works for whatever is changing your files, so mds_stores spikes often line up with something else: a dependency install, a build, an AI agent rewriting a project, or a big download. Spare shows development projects and AI agents grouped by project folder, so you can see what was active when indexing kicked in.
Spare treats mds_stores as a system task and never offers to stop it.
Common questions
About mds_stores
Is mds_stores a virus?
No. It is part of Spotlight and lives inside macOS’s system frameworks. It runs on every Mac with Spotlight indexing turned on.
Why does mds_stores run so much after a macOS update?
Updates can trigger Spotlight to reindex your disk. The work is temporary and usually finishes within a few hours, depending on how many files you have.
Can I turn off Spotlight to stop mds_stores?
You can exclude folders or disks in Search Privacy, which is usually enough. Turning off indexing entirely breaks Spotlight search and search in Finder and many apps, so it’s rarely worth it.
Does rebuilding the Spotlight index make my Mac faster?
Not by itself. It fixes missing or wrong search results. Rebuilding also means mds_stores works hard again until the new index is complete.
Related processes
Sources: Apple: Rebuild the Spotlight index on your Mac, The Eclectic Light Company: Using and troubleshooting Spotlight in Sequoia. Reviewed October 6, 2026.
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macOS 14+ · Apple silicon · Signed and notarized