Myth: 'repair disk permissions' fixes a slow or buggy Mac — via Howard Oakley, The Eclectic Light Company

MythmacOS 14 Sonoma and later

Repairing permissions was standard Mac advice until OS X El Capitan, when System Integrity Protection arrived and Disk Utility dropped the feature. System files are protected from getting wrong permissions in the first place, and Apple hasn't recommended repairing home-folder permissions since Big Sur.

What to do instead

Don't use third-party 'permission repair' tools, and don't run repairHomePermissions from Recovery: Howard Oakley warns it can lock you out of your own home folder.
If one app misbehaves because of a corrupt settings file, quit it and reset just its preferences with defaults delete followed by the app's domain (for example com.example.app). The app recreates them on next launch.
Use Disk Utility's First Aid for actual disk errors.

Resetting an app's preferences loses its settings, so note anything you'll want to set again.

Sources

Should you repair permissions? — by Howard Oakley, The Eclectic Light Company

Source reviewed: 2026-11-02
Link checked: 2026-11-02
Tested hands-on: Not by Oddbyte.Me

Oddbyte.Me hasn't tried this on every macOS version, so keep the undo handy.

repair permissionsdisk utilityfirst aidsipmyth

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Myth: 'repair disk permissions' fixes a slow or buggy Mac — via Howard Oakley, The Eclectic Light Company

What to do instead

Sources

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