When someone enters wrong login credentials in WordPress login page, the screen shakes. If you don’t like this feature of WordPress then remove it.

All you have to do is add following given hack in your active theme’s function.php file:

function my_login_head() {
remove_action(‘login_head’, ‘wp_shake_js’, 12);
add_action(‘login_head’, ‘my_login_head’);

Now check your login screen. No more shaking.

Or, simply install and activate Remove Wrong Password Shake plugin. It does the same thing.