Which folders in ~/Library are safe to delete, and which will cost you
A folder by folder verdict on your Library, with what each one holds and what happens if it is gone.
~/Library is where most of a Mac's reclaimable space is, and it is also where the worst mistakes happen, because the folder holds disposable caches and irreplaceable data side by side with no visual difference between them.
The verdict, folder by folder
| Folder | What it holds | Safe to delete |
|---|---|---|
Caches | Rebuildable cache | Yes, per folder inside |
Logs | Diagnostics | Yes |
Saved Application State | Window positions | Yes |
Application Support | App data and caches mixed | No, look inside first |
Containers | Sandboxed app data | No, same reason |
Group Containers | Shared app data | No |
Preferences | Settings | No, you lose configuration |
Mail | Local mail copies | No without checking the server |
Messages | Message history and attachments | No |
Developer | Xcode caches and archives | Mixed, see the Xcode guides |
Mobile Documents | iCloud Drive local copies | No, evict instead |
Fonts | Your installed fonts | Only ones you added |
The rule that covers the ambiguous cases
If the folder's name contains Cache, or its contents are named after something that could be downloaded again, it is safe. If you cannot tell what would be lost, open it. Two minutes of looking is cheaper than restoring a password manager's local database.
The three folders worth attacking first
Caches, per subfolder, largest first. This is where the space is.Logs, entirely, though it is usually small.Saved Application State, entirely, which also fixes apps reopening dead documents.
du -sh ~/Library/* 2>/dev/null | sort -h | tail -15
du -sh ~/Library/Caches/* 2>/dev/null | sort -h | tail -15What to do with the folders you cannot delete
Most of them have a supported way to shrink: clearing website data in a browser, setting a cache limit in an app, evicting cloud files, or removing an account. Those are the routes in what is in your Library folder and what Containers hold.
Common questions
Is it safe to delete the Library folder on a Mac?
Not the folder itself, which holds your settings, mail, messages and app data. Specific folders inside it are safe: Caches, Logs and Saved Application State can all be cleared.
What can I safely delete in ~/Library?
Caches, Logs and Saved Application State. Application Support, Containers, Preferences, Mail and Messages all hold data that is not recreated, so they need inspecting rather than deleting.
How do I know if a Library folder is safe to remove?
If it is named as a cache, or holds files that could be downloaded again, it is safe. If you cannot tell what would be lost, open it and look, because names alone do not distinguish cache from data.
Why do apps break after cleaning Library?
Usually because a folder was removed while the app was running, or because Preferences or Application Support was cleared. Quit the app first and move things to the Trash so mistakes are recoverable.