3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php var_dump($_SERVER['HTTP_REFERER']);
Output for 5.3.0 - 7.1.0
Notice: Undefined index: HTTP_REFERER in /in/enUP0 on line 2 NULL
Output for 4.3.0 - 5.2.17
Notice: Undefined index: HTTP_REFERER in /in/enUP0 on line 2 NULL