Exclude category from homepage

1.  
2.  
3.  
4.  
5.  
6.  
7.  
8.  
9.  

<?php
function excludeCat($query) {
  if ( $query->is_home ) {
    $query->set('cat', '-3,-5,-23');
  }
  return $query;
}
add_filter('pre_get_posts', 'excludeCat');
?>

Instructions:

To exclude some categories from the the loop on the frontage, you can use this snippet in your function.php.

3, 5, and 23 are the IDs of the categories and the - makes them go away.