You updated macOS, restarted, and now your MacBook feels slower than it did before the update. Apps bounce in the Dock forever, the fans spin up while you are doing nothing, and Spotlight search comes back empty. Here is the honest answer most people never get told: a Mac is supposed to be slow for a little while after a macOS update, and there is a specific list of background jobs causing it. This guide tells you which slowdowns are normal (and how long to wait), and which ones mean something is actually wrong.
First: is this the normal "settling-in" slowdown?
Right after a major macOS update or upgrade, your Mac quietly runs several one-time jobs in the background. They all fight for the CPU and disk at the same time, which is exactly why the machine feels sluggish for the first few hours (sometimes into the next day on an older Mac):
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Spotlight is rebuilding its search index. Every file on the drive gets re-catalogued so search works again. Until it finishes, searches are slow or empty and
mds/mds_storeseat CPU. - Photos is re-analyzing your library. Faces, scenes, and "Memories" get reprocessed after an update. On a big library this alone can run for hours and pin a CPU core.
- iCloud and Messages are re-syncing. The update can reset sync state, so your Mac re-downloads and re-verifies data.
- The system is optimizing app caches. macOS recompiles and re-caches parts of apps the first time you launch them after an update.
The tell that it is normal: the slowness showed up immediately after the update, the fans are busy, and it is slowly getting better on its own. The fix here is patience — leave the Mac awake, plugged in, and connected to Wi-Fi for a few hours (overnight is ideal) and let it finish.
How to confirm it is just background jobs
Open Activity Monitor (Spotlight it, or find it in Applications › Utilities) and click the CPU tab. If the top processes are named things like mds, mds_stores, mdworker, photoanalysisd, photolibraryd, cloudd, or bird, that is the settling-in work. It will stop on its own. Do not force-quit them — you will just make them start over.
If it has been more than a day: work down this list
If your Mac is still slow 24+ hours after the update, the background jobs should be long done and something else is holding it back. Do these in order and stop when it is fast again.
- Restart once more. A second clean restart after the update clears the temporary state the update left behind. This alone fixes a surprising number of "slow after update" cases.
- Check for a leftover incompatible app or login item. Old menu-bar utilities, VPNs, antivirus, and "cleaner" apps are the #1 cause of a Mac that got slow the day it updated. Go to System Settings › General › Login Items & Extensions and turn off anything you do not recognize or need, then restart. If speed returns, re-enable them one at a time to find the culprit.
- Confirm Spotlight actually finished. If search is still slow or empty after a day, the index is stuck. See our guide on fixing Spotlight and rebuilding the index.
- Make sure the drive is not full. A big update eats free space, and a nearly-full drive makes any Mac crawl. Aim for at least 10–15% free. Our storage-full fix guide walks through clearing it safely.
- Update your apps. After a macOS jump, older versions of apps run in a slow compatibility mode until you update them. Update everything in the App Store and check each app's own updater.
The part nobody likes: sometimes the update just exposed an old Mac
Each new macOS asks a little more of the hardware. If your Mac is an older Intel model, or has only 8GB of RAM and a small SSD, a new macOS version can genuinely make it slower for good — not because anything is broken, but because the machine is now at its limit. If you have waited it out, cleared space, and pruned login items and it is still painful, this is likely where you are. Our full MacBook running slow guide covers how to tell age-slowness from software-slowness, and how much RAM you actually need.
If it is time to move on, a newer Apple-silicon Mac will not have this problem for years. A refurbished M1 MacBook Air starts at $450 at LuxuriousComputers, and it will run the latest macOS smoothly. It is also worth checking the Apple clearance section for the lowest prices we have. Every Mac ships free with a 1-year warranty, and you can put your slow old MacBook toward it with a trade-in quote — even if it barely turns on.
Before you buy: was the update worth it?
If you are still deciding whether to install a new macOS version at all, read how to update macOS the safe way first — the biggest cause of post-update misery is jumping to a brand-new major version on an old Mac on day one.
Related guides
- MacBook running slow? Every fix in order
- How to update macOS safely
- Spotlight not working? Rebuild the index
- MacBook storage full? How to free space
Frequently asked questions
Is it normal for a Mac to be slow after a macOS update?
Yes. For the first few hours after a major update, macOS rebuilds the Spotlight index, re-analyzes your Photos library, and re-syncs iCloud in the background. These one-time jobs make the Mac feel sluggish and run the fans. Leave it plugged in and awake, and it should return to normal within a few hours to a day.
How long does a Mac stay slow after updating?
On a newer Apple-silicon Mac with a modest Photos library, usually an hour or two. On an older Mac or a large library, it can run overnight. If it is still slow after 24 hours, the background jobs are done and you should work down the checklist above.
My Mac got slow the day I updated and never recovered. What is the top cause?
An incompatible login item or menu-bar app — old VPNs, antivirus, and "cleaner" utilities are the usual suspects. Turn them off in System Settings › General › Login Items & Extensions, restart, and see if speed returns.
Should I force-quit mds or photoanalysisd to speed things up?
No. Those are the background indexing jobs. Force-quitting them just makes macOS start the work over, so it takes longer overall. Let them finish.
Will resetting or reinstalling macOS fix a slow Mac after an update?
Reinstalling macOS (your files stay) can help if the update left something corrupted, but try the restart, login-item, and storage steps first — they fix most cases without the hours a reinstall takes. If your Mac is old and at its RAM limit, no reinstall will make it fast again; that is a hardware ceiling, not a software bug.