How to fix macOS Sonoma or Sequoia system lag caused by Spotlight indexing after an update

Summary

This guide helps you troubleshoot and resolve: How to fix macOS Sonoma or Sequoia system lag caused by Spotlight indexing after an update. Follow the steps below to fix the issue.

Common Causes

After a major macOS upgrade to Sonoma or Sequoia, your Mac may suddenly feel sluggish, the fans may spin up loudly, and battery life may drop noticeably. In most cases, this is caused by Spotlight silently rebuilding its search index in the background. Spotlight indexing is CPU- and disk-intensive, and it can take anywhere from a few hours to a few days depending on the size of your drive. This article explains what is happening, how to confirm Spotlight is the cause, and how to speed the process along or reset the index if it gets stuck.

Quick Fix Steps

If you only have a minute, run through these steps first. They resolve the issue for most users within a few hours.

1. Leave your Mac plugged into power and connected to Wi-Fi so Spotlight can finish indexing.
2. Open System Settings > Siri & Spotlight and temporarily uncheck any locations you do not need indexed (such as external drives or large media folders).
3. Quit any apps you are not actively using to free up CPU and RAM for the indexing process.
4. Allow the Mac to run overnight or during a period of low use. Spotlight will generally complete its initial pass within 24 to 48 hours.
5. If performance is still poor after 48 hours, follow the Detailed Instructions below to reset the Spotlight index.

Detailed Instructions

Confirm Spotlight Is the Cause

Before resetting anything, check that Spotlight is genuinely the source of the slowdown.

1. Open Activity Monitor (find it via Spotlight or in /Applications/Utilities/).
2. Click the CPU tab and sort by the % CPU column.
3. Look for processes named mdworker_shared, mdworker, or Spotlight. If one or more of these is consistently using a high percentage of CPU, Spotlight indexing is the cause.
4. Click the Energy tab and check whether mdworker_shared is listed with a high energy impact. This explains the fan noise and battery drain.

Reduce the Indexing Workload

You can shorten the indexing time by removing locations Spotlight does not need to scan.

1. Open System Settings > Siri & Spotlight.
2. Scroll down to Spotlight Privacy.
3. Drag any large folders, external drives, or network shares into the list. Spotlight will ignore these until you remove them.
4. Close the window and let Spotlight re-index the remaining locations.

Reset the Spotlight Index Completely

If Spotlight appears stuck (no progress after several hours, or CPU usage stays pinned at 100%), a full reset usually clears the problem.

1. Open System Settings > Siri & Spotlight.
2. Scroll to Spotlight Privacy.
3. Click the + (plus) button and select your Macintosh HD (or / if your startup volume has a different name). This tells Spotlight to stop indexing everything.
4. Wait a few seconds, then click the - (minus) button to remove Macintosh HD from the list. Spotlight will begin a fresh index of your drive.
5. Close System Settings and leave the Mac running. Initial indexing can take several hours depending on drive size and the number of files.

Rebuild the Index via Terminal (Advanced)

If the System Settings method does not trigger a rebuild, you can force it from the command line.

1. Open Terminal from /Applications/Utilities/.
2. Run the following command to turn off indexing:

   sudo mdutil -a -i off

3. Run this command to turn indexing back on:

   sudo mdutil -a -i on

4. Enter your administrator password when prompted.
5. Restart your Mac and allow Spotlight to rebuild the index from scratch.

Troubleshooting

Spotlight Indexing Will Not Start

• Confirm your drive is formatted as APFS or Mac OS Extended (Journaled). Spotlight cannot index drives formatted as NTFS or FAT.
• Open System Settings > Siri & Spotlight and ensure the Search Results toggles for the categories you want are switched on.
• Try the Terminal method above to force a rebuild.

Spotlight Search Returns No Results

• Wait for indexing to finish. Searching before the index is complete will return incomplete results.
• Check the Spotlight Privacy list and make sure the file or folder you are searching for has not been excluded.
• Reset the index using the steps in Reset the Spotlight Index Completely.

High CPU Usage Persists After Several Days

• Open Activity Monitor and check whether mdworker_shared is still active. If it is not running, another process is responsible for the slowdown.
• Boot into macOS Recovery (restart and hold Command + R) and run Disk Utility > First Aid on your startup volume to rule out disk errors.
• Check for pending macOS updates in System Settings > Software Update. Apple often releases follow-up updates that fix indexing bugs introduced in major releases.

Third-Party Security or Antivirus Apps Interfering

Some security applications hook into Spotlight and can prevent the index from completing. If you have recently installed or updated one of these apps, try the following:

1. Temporarily disable the third-party security app.
2. Reset the Spotlight index using the steps above.
3. Re-enable the security app once indexing is complete.
4. If the problem returns, contact the security app vendor for a Sonoma or Sequoia-compatible update.

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