How to Disable New User Registrations in WordPress Easily

Code

// Function to disable new user registration in WordPress
function wp_dudecom_disable_user_registration() {
    // Remove the 'Anyone can register' option from the General Settings
    update_option('users_can_register', 0);
}

// Hook the function to 'init' to ensure it runs on every page load
add_action('init', 'wp_dudecom_disable_user_registration');

// Function to remove the registration link from the login form
function wp_dudecom_remove_register_link($link) {
    // Check if the link is for registration and return an empty string if true
    if (strpos($link, 'wp-login.php?action=register') !== false) {
        return '';
    }
    return $link;
}

// Hook the function to 'register' filter to modify the registration link
add_filter('register', 'wp_dudecom_remove_register_link');

// Function to redirect users trying to access the registration page
function wp_dudecom_redirect_registration_page() {
    // Check if the current page is the registration page
    if (isset($_GET['action']) && $_GET['action'] === 'register') {
        // Redirect to the home page
        wp_redirect(home_url());
        exit;
    }
}

// Hook the function to 'login_init' to check for registration page access
add_action('login_init', 'wp_dudecom_redirect_registration_page');