MacBook Pro storage severely decreases by 120 GB after OS 27 update..but appears to 'normalize' after fiddling with Spotlight?

Updated MBP to OS 27 and storage says it went from 582 GB to 460 GB. Called Apple Support and after trying a bunch of things, they went to a supervisor who said to change some things on Spotlight....so I did that, and the storage amount normalized.....meaning it was 582 before the update and after the update it is 562.

This morning, I updated my older MBP to OS 27, and the exact same thing happened......storage shows it decreased by 120 GB from ~ 585 to 465. Apple was doing a callback today to see how the spotlight changes worked on the new MBP...so I let them call back to get the info on how to work with Spotlight. A different person called me back today. She said was looking at the notes then disconnected me.

I called again, and this new person didn't understand what I was saying, so they just bumped me up to the Tech supervisor, He didn't understand either . He said there were no notes. But the 1st person was reading the notes..??. New Tech Superv said I must've lost data and should check for that...........except the numbers on the new MBP 'normalized' back to 562 after doing something with spotlight...so I didn't lose anything. I said this multiple times....I just wanted to reproduce the Spotlight steps. But he said Spotlight has nothing to do with storage and t here were no notes. I should check it all manually to see if I have lost anything :/ My older MBP will not 'normalize' w/o doing the adjustment in spotlight, apparently. Does anyone have ANY ideas even outside Spotlight, that could help me get to accurate storage now that I've talked with 5 Apple people in 2 days? TIA

Posted on Sep 26, 2026 1:36 PM

2 replies

etresoft

Level 9 (60,836 points)

Sep 26, 2026 2:52 PM in response to C735

C735 wrote:

Does anyone have ANY ideas even outside Spotlight, that could help me get to accurate storage now that I've talked with 5 Apple people in 2 days? TIA

This is completely normal and typical behaviour. Storage problems have been one of the most common problems for the past several years.

The reason is fairly straightforward. People are addicted to updates and updates are always 15+ GB in size. And that's compressed. It has to be expanded. That takes more storage. And recently, Apple has really gone disk image crazy. If you go poking around, you'll find many dozens of 8+ GB disk images. And this year, add on 10-40 GB of AI models.

And that just scratches the surface. It sounds like you really aren't having any storage problem at all. I say don't worry about it. It also probably doesn't have anything to do with spotlight. The system manages storage on your behalf, and it doesn't do it well. When you, or it, tries to delete a file, it may take a couple of days for the storage to finally be released.

C735 Author

Level 1 (4 points)

Sep 27, 2026 8:41 AM in response to etresoft

Theoretically I get what you are saying but it hasn't been true for me.

I have two MBP....long story. They have almost identical info on them.

I updated the newer one. In a week, there was no change in the 120 GB drop.....so I called Apple and got the person who said 'change these things in spotlight', and I did and within 24 hours, that computer adjusted the storage to using about 22 GB drop total on the new download.

I updated the older MBP yesterday am, and no change in 24 hours. I expect it will be like the newer one where the 120 GB drop will not resolve unless I can help it.

Maybe spotlight isn't the remedy, but it worked......I'm open to anything that works

Originally posted at discussions.apple.com/thread/256365611