What is mds_stores on a Mac? Spotlight indexing explained

27 October 2026 · 6 min read

mds_stores is the process that builds and updates the Spotlight search index, the catalogue macOS uses to find files, mail and apps when you search. It is busy after something changes a lot of files, such as a macOS update, a restore from backup, copying in a large folder or a first start on a new Mac. The best thing to do is leave it alone until it finishes, because it stops by itself. If it keeps coming back, you can keep the busy folders out of the index in System Settings.

What mds_stores does

Spotlight is fast because it does not search your disk when you type. It searches an index made earlier: a list of the names, contents and details of your files, kept ready. mds_stores is the process that writes that index and keeps it up to date. It belongs to a small group of Spotlight processes that work together.

mds manages the index. Foreman calls it “Spotlight index server”.
mds_stores builds and updates it. Foreman calls it “Spotlight indexing”.
mdworker and mdworker_shared read new and changed files so they can be searched. Foreman calls them “Spotlight file reader”. Several copies often run at once, and Foreman groups them into one row with a count, such as “Spotlight file reader (4)”.

Foreman is a Task Manager for macOS, and these names are the plain ones it shows beside the real names in grey. Foreman describes mds_stores as: builds and updates the Spotlight search index, busy after big file changes or updates.

Why it is busy

mds_stores works whenever the index is out of date. These are the common moments.

After a macOS update. Big updates often rebuild parts of the index, and the Mac may be busy for hours afterward. If your Mac slowed after an update, why is my Mac slow after a macOS update has the wider picture.
After setting up a new Mac or restoring from a backup. All your files are new to the Mac, so everything has to be read once.
After copying or downloading many files. A large photo library, a code folder with thousands of small files, or a mail archive gives it a lot to read.
After connecting an external drive. Spotlight indexes drives that are attached to the Mac, which can take time for a large one.
After you take a folder off the privacy list. Spotlight then has to read everything in it.
Folders that change all the time. A folder full of build files, a cache or a database that changes all day keeps the index working again and again.

Because the workload is mostly reading files, you may also see high disk activity and a warm Mac while it runs. It is working hard, but it is not a fault.

Let it finish

Indexing is a one-off job after each big change, and the index only has to catch up. macOS treats it as background work, so it tends to give way when you are busy and gets more done when you step away. A Mac left awake on power overnight often finishes.

Signs that it is finishing normally: the CPU use for mds_stores and the Spotlight file readers falls over time, and Spotlight search starts to return files that it could not find earlier. If you search for something in Spotlight while it is still indexing, results can be missing or incomplete until it finishes. That is a sign it has not finished, not a sign that it is broken.

The one thing to avoid is ending the processes over and over. macOS starts them again, the work picks up where it can, and the job only takes longer.

You can read more about the reader processes in what is mdworker_shared on a Mac and why are there so many.

How to see how much it is using

Open Foreman with Control-Shift-Escape and look at the Processes page, where mds_stores shows as “Spotlight indexing”. Click the CPU column to sort and you can see how it compares with everything else. mds_stores is owned by the system, so Foreman shows no disk figures for it. To see whether the disk is busy, open the Performance page and pick Disk for its live read and write graph. If the Spotlight file reader row is busy, and the numbers drop over an hour or two, indexing is moving along.

You do not need to end anything. If you want the Mac quicker in the meantime, close the heavy apps you are not using, so Spotlight and the apps are not competing.

Keep folders out of the index

If mds_stores is busy again and again, the usual cause is a folder that changes constantly and that you never search. You can tell Spotlight to leave it alone.

Open System Settings and choose Spotlight in the sidebar. On macOS 14 Sonoma it is Siri & Spotlight.
Click Search Privacy (Spotlight Privacy on Sonoma), near the bottom.
Add the folders or drives you want Spotlight to skip, using the plus button, or by dragging them in.
Click Done.

Good candidates are folders of build output, large virtual machine files, a scratch disk for video editing, downloads you rarely search, and archives on a drive. Spotlight then stops indexing them, and the index gets smaller as well.

The trade-off is plain: files in those folders will not show up in Spotlight searches. You can still find them in Finder.

In the same Spotlight settings you can also choose which kinds of result Spotlight shows, such as applications, documents or mail. Those switches only change what appears in the results. They do not stop the files being indexed, so they will not calm mds_stores.

Do not turn indexing off for good

Some advice online tells you to switch Spotlight off completely. It is better not to. Spotlight is what lets you open apps from the keyboard, find a document by what is in it and search your mail. Other parts of macOS use the index too. Switching it off trades a few busy hours for a Mac that cannot find things.

When it never settles

If mds_stores is still working hard after a day or two on a Mac that is plugged in, awake and idle, something is stuck. Try these, in this order.

Restart the Mac. This is the first thing to try, and it clears a good many stuck states.
Check that there is free space on the disk. Look in System Settings under General, then Storage. A nearly full disk makes everything slower, indexing included.
Look for a folder that changes all the time and add it to Search Privacy.
If a certain drive is the problem, add it to Search Privacy as well.
If it still fails, rebuilding the index is the last resort. Apple’s way needs no Terminal: in Search Privacy, add the disk (or the folder that seems stuck) to the list, then select it, click the minus button and click Done. Spotlight then indexes it again from scratch. That makes the Mac busy for hours, so choose a time when you will not need it.

Is mds_stores safe

Yes. It is part of macOS, made by Apple, and it does what its name suggests. It is not a virus, and a high figure for it is not a sign of one. A process with a similar name that is not located in the system folders would be a reason to look closer.

In short

mds_stores builds the Spotlight index. It gets busy after updates, restores and big file changes, and it calms down by itself, so let it finish. If it keeps returning, add the folders that churn to Search Privacy in System Settings. Foreman, $12 once and free for 24 hours, names these processes in plain English, groups the Spotlight readers together and shows how much of the Mac they are using.