What Is ~/Library/Preferences on Mac?
Your user folderUpdated
- Full path
~/Library/Preferences
- Scope
- Your user folderInside your home folder — one copy per user account.
- Freshist & this folder
- Freshist checks this folder when uninstalling an app. When you uninstall an app, Freshist looks here for items that belong to it. Matches on the app's bundle ID can be pre-selected; name-only guesses are labeled “not sure” and never pre-selected. Removed items go to the Trash, so you can undo.
From Freshist's own cleaning rules — the same catalog the app uses.
How macOS stores settings
When an app remembers your window layout, toolbar choices, default folder or "don't show again" checkboxes, it usually does so through the user defaults system. macOS writes those values to a property list in ~/Library/Preferences, named after the app's bundle ID: Finder's is com.apple.finder.plist, and a third-party app might use com.example.Editor.plist. Global settings shared by every app live in .GlobalPreferences.plist. A few apps create their own subfolders here as well.
Two related places are worth knowing:
- Sandboxed apps, including most Mac App Store apps, keep their preferences inside their container, under
~/Library/Containers/<bundle ID>/Data/Library/Preferences. See the Containers guide. - Per-Mac settings go into the ByHost subfolder, with the Mac's hardware UUID in the file name.
What deleting a preference file does
| You delete | Result |
|---|---|
| A .plist for an app you uninstalled | Nothing visible. The file was unused. |
| A .plist for an app you still use | The app starts with default settings |
| An app's .plist that held its license | You may need to enter the license again |
.GlobalPreferences.plist or com.apple.* files | System-wide settings reset; avoid |
Resetting an app's preferences is a classic fix for an app that crashes on launch or behaves oddly. The cost is losing your customizations, and with some apps your registration or sign-in, because developers sometimes keep licenses and account tokens in the same file. Passwords themselves normally sit in the keychain, not here.
The space involved is small. A whole Preferences folder is usually a few megabytes, so clearing leftovers is about tidiness, not storage.
Looking without changing anything
ls ~/Library/Preferences | head -40
du -sh ~/Library/Preferences
defaults read com.example.Editor
plutil -p ~/Library/Preferences/com.example.Editor.plist
defaults domains lists every preference domain your account has. Replace com.example.Editor with the bundle ID you're interested in. You can find an app's ID with osascript -e 'id of app "AppName"'.
Resetting one app the safe way
- Quit the app completely.
- Keep a copy first:
defaults export com.example.Editor ~/Desktop/editor-prefs.plist. - Run
defaults delete com.example.Editor, or move the.plistto the Trash in Finder. - Open the app again and check that it starts clean.
If something important was lost, quit the app and restore the copy with defaults import com.example.Editor ~/Desktop/editor-prefs.plist.
Leftovers after uninstalling an app
Uninstalling by dragging an app to the Trash leaves its preference file behind. That's harmless, and it has an upside: if you reinstall later, your settings come back. When you want a clean removal, look for files that begin with the app's bundle ID, plus any folder named after the developer. Leave anything starting with com.apple. alone unless you're following specific troubleshooting steps. Some of those files hold settings you'd have to rebuild by hand.
The Application Support and Caches folders usually hold far more of a removed app's data than Preferences does.
Sources
- About preferences and settings (Apple Preferences and Settings Programming Guide)
- UserDefaults (Apple Developer Documentation)
man defaultsandman plutilin Terminal
Frequently asked questions
I deleted an app's .plist but the old settings came back. Why?
macOS caches preferences in a background process called cfprefsd. If the app was running, or cfprefsd still held the values, they can be written back. Quit the app first, or use defaults delete, which goes through cfprefsd.
Can I open a .plist file to see what's inside?
Yes. Most are binary, so use plutil -p followed by the path in Terminal, or defaults read with the bundle ID. Both only read the file.
Do I need to back up Preferences before migrating to a new Mac?
Migration Assistant and Time Machine both include it. A manual copy is only worth it if you want to keep a single app's setup before resetting it.