In this post I will show you how to change login error message on a wordpress website. It is needed because default error messages prints username which is not good for wordpress website security.
To change wordpress login error message you have to add a filter using login_errors.

Just add following lines of code inside your current themes functions.php file inside a php code. This code will change login error message to a custom error message.

// Use a Custom Error message on wordpress login page for Better Security
function snilesh_custom_login_errors(){ 
    return ' <strong>ERROR</strong>: Please check your username and password. ';

add_filter( 'login_errors', 'snilesh_custom_login_errors' );