If you have a WordPress site that you allow people to sign up for, you often don’t want them to be able to access wp-admin. It’s not that there are any security issues, you just want to ensure that your users are accessing your site in a predictable manner.

To block non-admin users from getting into wp-admin, you just need to add the following code to your functions.php, or somewhere similar:

add_action( 'init', 'blockusers_init' );
 
function blockusers_init() {
	if ( is_admin() && ! current_user_can( 'administrator' ) ) {
		wp_redirect( home_url() );
		exit;
	}
}

Ta-da! Now, only administrator users can access wp-admin, everyone else will be re-directed to the homepage.