3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php session_start(); ?> <?php header('Location: http://google.com');
Output for 7.0.20, 7.1.5 - 7.2.0
Warning: Cannot modify header information - headers already sent by (output started at /in/bipEi:6) in /in/bipEi on line 9
Output for 5.3.20 - 7.0.6, 7.1.0
Warning: Cannot modify header information - headers already sent by (output started at /in/bipEi:7) in /in/bipEi on line 9