3v4l.org

run code in 300+ PHP versions simultaneously
<?php $str = ''; for ($i = 0; $i < 1e4; $i++) { $str .= md5(time()); } echo strlen($str); $memory = memory_get_usage(true); substr($str, 0); echo memory_get_usage(true)-$memory;

preferences:
34.25 ms | 402 KiB | 5 Q