How to Show Hidden Files on Mac

Step by step

1. 10 sec

   Open the folder you want to inspect

   Click the Finder icon in the Dock, then open the folder you want to look at. Your home folder is a reasonable place to start, since most applications keep their preference dotfiles there. Press Shift + Command + H to jump straight to it from any Finder window.

   Note: Hidden files are not encrypted and not protected. They are ordinary files whose names begin with a period. That is the entire mechanism.
2. 1 sec

   Press the show hidden files combo

   Hold Command and Shift, then press the period key. Greyed-out files and folders appear immediately: .DS_Store, .localized, and whatever else the folder is carrying. Press the same three keys again to hide them. The setting applies to every open Finder window, not only the front one.

   Note: They will tell you this is a power-user trick. It is a keyboard toggle Apple shipped long ago and never bothered to advertise.
3. 5 sec

   Use the same combo in Open dialogs

   The toggle also works inside any Open or Save dialog. Bring up a file picker in an app, press the same three keys, and the hidden items appear in the list. This is the fastest route to a folder like the user Library when an app refuses to browse there.

   Note: In those same dialogs, Command + Shift + G opens a Go to Folder field where you type an exact path and skip the browsing entirely.
4. 30 sec

   Make the change permanent in Terminal

   Open Terminal from Applications > Utilities. Type defaults write com.apple.finder AppleShowAllFiles -bool true and press Return. Then type killall Finder and press Return. The Finder quits and relaunches, and hidden files stay visible in every window from then on, across restarts.

   Note: killall Finder is not dangerous. It stops the Finder process and the system starts it again within a second. Your open Finder windows do close.
5. 30 sec

   Reverse the Terminal setting

   Run defaults write com.apple.finder AppleShowAllFiles -bool false in Terminal, then run killall Finder again. The keyboard toggle still works afterwards, so you keep the on-demand view without the permanent clutter. That is the arrangement most people settle on once the novelty wears off.

   Note: You can write the value as NO instead of false and it is accepted. The boolean form is clearer when you read the command back later.
6. 0 sec

   Leave the system dotfiles alone

   Look, do not delete. Files beginning with a period belong to macOS and to the applications you installed. The file .DS_Store holds folder view settings, .localized marks a folder for translated names, and the dotfiles in your home folder hold app configuration. Removing them breaks behavior with no warning.

   Note: The Finder rebuilds .DS_Store the moment you open that folder again, so deleting it accomplishes nothing except a slower first look.