3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $ip=$_SERVER['REMOTE_ADDR']; $ua=$_SERVER['HTTP_USER_AGENT']; $ref=$_SERVER['HTTP_REFERER']; echo $ref; ?>
Output for 5.3.0 - 5.6.28, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
Notice: Undefined index: REMOTE_ADDR in /in/i4f0d on line 2 Notice: Undefined index: HTTP_USER_AGENT in /in/i4f0d on line 3 Notice: Undefined index: HTTP_REFERER in /in/i4f0d on line 4
Output for 4.3.0 - 5.2.17
Notice: Undefined index: REMOTE_ADDR in /in/i4f0d on line 2 Notice: Undefined index: HTTP_USER_AGENT in /in/i4f0d on line 3 Notice: Undefined index: HTTP_REFERER in /in/i4f0d on line 4