3v4l.org

run code in 300+ PHP versions simultaneously
<?php $var = "lol"; if(isSerialized($var) === true){ unserialize($var); } else { echo "KO"; } function isSerialized($str) { return ($str == serialize(false) || @unserialize($str) !== false); }

preferences:
38.35 ms | 402 KiB | 5 Q