Lost Storage After the macOS 27 Update? Here's Why

Written for macOS 27.0 Golden Gate on Apple silicon Macs.

Apple released macOS 27 Golden Gate on September 14, 2026, and a lot of people noticed the same thing right after upgrading: much less free space than before. For some, the drop was big enough to trigger low-storage warnings.

Part of that space comes back by itself. The rest can be explained, and some of it you can reclaim safely. The order matters here: wait first, then look, and delete only once you know what you're deleting.

#Key takeaways

• Some of the drop is temporary. Update files, a pre-update snapshot and re-indexing usually settle within 24 to 48 hours.
• Apple Intelligence models are the biggest lasting change. Apple lists up to 14 GB on Macs with M3 or later and at least 12 GB of memory, and up to 8 GB on other supported Macs.
• System Settings has no button that deletes the AI models, and turning features off doesn't reliably give the space back.
• The space you can reclaim yourself is usually in installers you kept, old device backups and app caches.
• Deleting system folders is not a way to get space back after an update.

#Why does the macOS 27 update use so much space?

Three things take the space, and each behaves differently.

1. Temporary update files and a safety snapshot. Apple advertised the upgrade download at about 30.8 GB. The installer needs that download plus working room. Since macOS High Sierra, Apple has also saved a local Time Machine snapshot before installing any macOS update. Apple says your Mac counts snapshot space as available storage and removes snapshots when space is needed or after 24 hours.

2. Re-indexing and housekeeping. After a major update, macOS rebuilds indexes and caches in the background. Spotlight and Photos are typical examples. While that runs, it takes up space and your Mac feels busier than usual.

3. Apple Intelligence models. Apple's next generation of Apple Intelligence requires macOS 27. Apple's own figures are up to 14 GB of on-device storage for Macs with M3 or later and at least 12 GB of unified memory, and up to 8 GB for other supported Macs. Independent reports show higher numbers in Storage settings, often 20 to 30 GB. Apple hasn't said whether its figure is measured the same way as the Storage readout.

The Eclectic Light Company tracked a Mac mini through the upgrade, and its numbers show the pattern clearly. Used space peaked about 150 GB above its previous level 24 hours after the upgrade. It then fell back, but stayed about 30 GB higher than before. Storage settings reported about 29 GB for AI components on that Mac. Your numbers will be different, but the shape (a big spike, then a smaller lasting increase) is common.

#Should I wait before cleaning up?

Yes. Give your Mac 24 to 48 hours after the upgrade before deciding anything. In the meantime:

• Keep it plugged in and awake for a while so background indexing can finish.
• Restart it once to clear some temporary files.
• If you use Time Machine, let it run a normal backup so pre-update snapshots expire on schedule.

Then look again. A day later, the "where did my space go?" question has often answered itself.

#How do I see what's taking the space now?

1. Choose Apple menu › System Settings, click General in the sidebar, then click Storage.
2. Wait for the bar to finish calculating, then hover over each segment. Look for Apple Intelligence (if listed), macOS, System Data, Applications, and iOS Files.
3. Click the info button next to Applications, Documents, iOS Files, and Trash to see the largest items.
4. To check for leftover snapshots, open Terminal and run this read-only command:

# Lists local Time Machine snapshots on the startup disk (read-only)
tmutil listlocalsnapshots /

5. Look in /Applications for an app named Install macOS Golden Gate. If you downloaded the full installer yourself and kept it, it can take a lot of space. You can delete it if you don't need it for a bootable installer.

If System Data is the big one, see what is System Data on Mac? for a breakdown. If caches turn out to be a large share, our cache guide covers which cache folders are safe to clear.

#What about Apple Intelligence: can you turn it off?

Apple's macOS 27 guide explains how to turn off or restrict individual features. There's no single master switch:

• Siri AI: System Settings › Siri › Turn Off Siri. You can then turn Siri back on and choose Use Siri Classic.
• Notification summaries: System Settings › Notifications › Summarize Notifications.
• Summaries in Messages and Mail: in each app's Settings.

Turning these off stops the features from running. Apple doesn't say it removes the model files, and owners report that the Storage figure doesn't reliably drop. If you're after disk space, these switches probably won't get it back.

You may come across scripts online that delete AI model folders. The models are system-managed assets, and we don't recommend deleting them by hand or disabling system protections to get at them.

#What can you safely remove after the update?

To clear local snapshots sooner, Apple's method is to open System Settings › General › Time Machine, click Options, set Backup Frequency to Manually, wait a few minutes, then set it back. Don't leave automatic backups switched off.

To remove old device backups, connect the iPhone or iPad, select it in the Finder sidebar, click Manage Backups on the General tab, right-click an old backup, and choose Delete.

Then check the usual places. Your Downloads folder, apps you no longer use (see how to uninstall apps completely), and developer caches are often worth more than anything the update added.

#What not to do

• Don't delete folders in /System or /System/Library/AssetsV2. macOS downloads and removes these assets itself.
• Don't disable System Integrity Protection to remove AI models.
• Don't panic-clean on day one. A good part of the drop goes away by itself.
• Don't switch off Time Machine permanently to get rid of snapshots. Turn it back on.
• Don't downgrade just for disk space. It means erasing and restoring, and the space is easier to find elsewhere.
• Don't trust "free 50 GB now" promises. No tool knows what it can free before it scans.

#A before-and-after view, if you want one

To see exactly which folders changed, a disk treemap helps: scan before and after cleaning and compare. Freshist's Analyze view is one option. It's hardlink-aware, so files aren't counted twice, and its cleaner lists every item and moves it to the Trash. Scanning is free. See the help docs or how it compares.

#Related guides

• What is System Data on Mac?
• Mac cleaner without a subscription: what to check
• MacBook fan loud or running hot? What's normal
• How to completely uninstall apps on Mac

#Sources

• Apple Support: How to get Apple Intelligence (storage requirements)
• Apple Mac User Guide: Turn off or restrict access to Apple Intelligence
• Apple Support: About Time Machine local snapshots
• Apple Mac User Guide: Change Storage settings on Mac
• Apple Support: Free up storage space on your Mac
• Apple Support: Locate backups of your iPhone, iPad, and iPod touch
• The Eclectic Light Company: How did Golden Gate affect free disk space?
• The Eclectic Light Company: Apple has released macOS Golden Gate
• MacRumors: Here are the Macs compatible with macOS Golden Gate