You updated macOS and now the disk is full. Here is what to check first
A major update leaves installer files, old snapshots and a reindexing job behind. Most of it clears itself, and the rest takes two commands.
- macOS Update
- Snapshots
- Storage
You install a major macOS update and afterwards the drive is tens of gigabytes fuller than before. This is common, mostly temporary, and worth understanding before you start deleting things you need.
What the update left behind
| What | Typical | Clears itself? |
|---|---|---|
| The pre-update APFS snapshot | 10 to 60 GB | Yes, within days |
| The installer app in Applications | 12 to 15 GB | No, delete it |
| Rebuilt system caches | 5 to 20 GB | Partly |
| Spotlight reindex working files | 2 to 10 GB | Yes, when indexing finishes |
| Previous system snapshot for rollback | Varies | Yes, on a schedule |
1. The installer, which nobody deletes
A macOS installer is 12 to 15 GB and it stays in your Applications folder after the update finishes. Check for it:
ls -la /Applications | grep -i "Install macOS"If it is there and the update is done, drag it to the Trash. You can download it again if you ever need it.
2. Snapshots, the big one
macOS takes a local snapshot before a major update so it can roll back. It is invisible in Finder and it is often the largest single item:
tmutil listlocalsnapshots /They are thinned automatically, usually within a few days. If you need the space now, ask macOS to reclaim it rather than deleting anything by hand:
tmutil thinlocalsnapshots / 20000000000 4That requests roughly 20 GB at urgency 4. This is the supported route and is the same mechanism macOS uses on its own.
3. Let Spotlight finish
A major update reindexes the whole drive. While it runs, the machine is slower and temporarily uses more space. Check whether it is still going:
mdutil -s /If indexing is enabled and in progress, leave it. Interrupting and restarting it costs more than waiting.
If it is still full a week later
Then the update is not your problem and something else is. The usual suspects have not changed: caches and Library, developer build output, and leftovers from apps you removed. Work through the general order instead.
Common questions
Why is my Mac disk full after a macOS update?
A major update leaves a pre-update snapshot for rollback, the installer app itself at 12 to 15 GB, and rebuilt caches. It also reindexes Spotlight, which temporarily uses more space. Most of it is reclaimed automatically within a few days, and the installer is the one part you have to delete yourself.
Can I delete the macOS installer after updating?
Yes. Once the update has completed, the Install macOS application in your Applications folder serves no purpose and is 12 to 15 GB. Move it to the Trash. If you ever need it again it can be downloaded from the App Store.
How do I remove APFS snapshots after an update?
Use tmutil thinlocalsnapshots with a target number of bytes and an urgency level, for example tmutil thinlocalsnapshots / 20000000000 4. That asks macOS to reclaim roughly 20 GB using its own mechanism, which is safer than attempting to delete snapshots directly.