Is it safe to use admin-ajax.php in the frontend?

See documentation here but don’t miss the note 2 and the following points :

  • AJAX on the front-end is more complicated, ajaxurl is not defined so
    you have to call it with wp_localize_script().
  • you have to use wp_ajax_nopriv_{action} for non logged in users
  • there could be security issue !!!

About the third point :

Be careful because you give access to non logged in users to some data and functions. So you need to ask yourself about what you want to do. It could seem a little bit too much but to me when using AJAX on the front-end of WP you should make $_GET things, only for reading, for example infinite scroll ans stuffs like that, not delete, create and update actions.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)