Restrict WordPress Login to Only Email Address or Username

By default, WordPress allows users to log in using either an email address or username. This setting will enable you to restrict logins to only accept email addresses, usernames or both.

• Email Address and Username (Default) – Allow users to log in using their user email address or username. This is the default WordPress behaviour.
• Email Address Only – Users can only log in using their email addresses. This disables logging in using a username.
• Username Only – Users can only log in using their user’s username. This disables logging in using an email address.