If you forget an app or server password on Mac
If you forget a password that has been stored in the keychain, you can have Keychain Access display it for you.
By default, the keychain password is the same as your computer login password.
Important: Don’t forget the login password for your computer. If you do, you won’t be able to view any of your other passwords in Keychain Access. See If your Mac keeps asking for your keychain password.
In the Keychain Access app on your Mac, select a keychain in the Keychains list.
Click Passwords in the Category list.
Double-click a keychain item.
Select the “Show password” tickbox.
Enter your keychain password.
To display your password, click Allow.