3v4l.org

run code in 300+ PHP versions simultaneously
<?php $data = 2; $length = 5; $text = substr( base64_encode( $data . microtime(true) ), 0, $length ); echo $text;
Output for 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.26, 7.3.0 - 7.3.13, 7.4.0 - 7.4.1
MjE0N

preferences:
129.26 ms | 403 KiB | 196 Q