How to Fix mds_stores High CPU on Mac

What Causes This?

mds_stores is part of macOS Spotlight indexing. It scans and organizes files so search results appear quickly, but CPU usage can spike when Spotlight is rebuilding its index, processing a large number of new or changed files, or getting stuck on corrupted metadata. This often happens after a macOS update, restoring files from backup, connecting an external drive, or when the disk is low on free space.

Common Symptoms

• Mac fans run loudly even when you are not doing much
• Activity Monitor shows mds_stores using a high percentage of CPU
• Spotlight searches feel slow or incomplete
• The Mac becomes hot, laggy, or drains battery faster than normal
• High CPU usage starts after adding many files or plugging in an external drive

How to Fix It Manually

1. Confirm that mds_stores is the problem

   1. Open Activity Monitor from Applications > Utilities.
   2. Click the CPU tab.
   3. Look for mds_stores in the process list and check whether it stays high for several minutes.

2. Wait if indexing recently started

   1. If you just updated macOS, restored files, or copied lots of data, Spotlight may simply be rebuilding its index.
   2. Leave the Mac plugged in and idle for a while, then check Activity Monitor again.
   3. If CPU usage drops after some time, no further action may be needed.

3. Restart your Mac

   1. Click the Apple menu > Restart.
   2. After logging back in, wait a few minutes and recheck Activity Monitor.
   3. Temporary indexing glitches often clear after a restart.

4. Exclude problem folders or drives from Spotlight

   1. Open Apple menu > System Settings.
   2. Go to Siri & Spotlight.
   3. Scroll down and open Spotlight Privacy or Search Privacy.
   4. Add folders, external drives, or locations with constantly changing files, such as backup folders, virtual machine images, or large archives.
   5. Remove any drive you do want indexed later after CPU usage settles.

5. Rebuild the Spotlight index

   1. Open Apple menu > System Settings > Siri & Spotlight.
   2. Open Spotlight Privacy.
   3. Drag your Macintosh HD into the privacy list to stop indexing it.
   4. Wait about a minute, then remove it from the list.
   5. Spotlight will rebuild the index from scratch, which can fix corrupted metadata causing mds_stores to loop.

6. Check available storage

   1. Open Apple menu > About This Mac > Storage or System Settings > General > Storage.
   2. Make sure you have a reasonable amount of free space available.
   3. Delete or move large unnecessary files if the disk is nearly full, since low storage can make indexing slower and less stable.

7. Disconnect or test external drives

   1. Safely eject external drives one at a time.
   2. Watch Activity Monitor after each one.
   3. If CPU usage drops, that drive may contain files Spotlight is struggling to index. You can exclude it from Spotlight privacy settings.

Fix It Automatically with Kudu

If you do not want to hunt through storage, caches, and problem files manually, Kudu can help speed up the cleanup process. It can identify clutter, free up disk space, and reduce the conditions that often cause indexing services like mds_stores to stay busy longer than they should.

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