Show hidden files in Finder

Run the following in a terminal to show hidden files in Finder. The defaults command updates the preference; killall Finder restarts Finder so the change takes effect.

defaults write com.apple.finder AppleShowAllFiles -boolean true && killall Finder

To hide them again, flip the boolean to false and run it again.

Update: May 2026

You don't need the terminal command. Since macOS Sierra, Finder has a built-in keyboard shortcut: ⌘⇧. (Command + Shift + period). Press it once and hidden files appear; press it again and they're gone. It works in Open/Save dialogs too.

The defaults command is still the right answer if you want hidden files visible permanently across sessions, or if you're scripting setup for a new machine.

Restored from the Wayback Machine. Body lightly edited; update section added.