3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php ob_start(); ob_end_flush(); header('foo');
Output for 4.3.0 - 5.2.2, 5.4.0 - 7.1.7
Output for 5.2.3 - 5.3.29
Warning: Cannot modify header information - headers already sent by (output started at /in/441e7:4) in /in/441e7 on line 6