// Remove Generator Completely

function remove_wp_generator() {
  return '';
}
add_filter('the_generator', 'remove_wp_generator');

// if you want your own text to appear rather than removing it...do this:
function my_custom_generator() {
  return 'This is my custom text';
}
add_filter('the_generator', 'my_custom_generator');

Place in your theme's  functions.php file. This removes the generator altogether, not just the version....making it more secure than simply removing the filter...

Remove wp_generator the "correct" way

wordpress

PHP