3v4l.org

run code in 300+ PHP versions simultaneously
<?php $utf8='η.∊'; var_dump($utf8, mb_convert_encoding($utf8,'CP1252','UTF-8'), mb_convert_encoding(mb_convert_encoding($utf8,'CP1252','UTF-8'),'UTF-8','CP1252') );

preferences:
54.05 ms | 402 KiB | 5 Q