3v4l.org

run code in 300+ PHP versions simultaneously
<?php $string = "\u263a\ufe0f"; var_dump(preg_replace('/\\\\u([0-9A-Za-z]{4})\\\\u([0-9A-Za-z]{4})/', ' $1$2', $string));

preferences:
55.23 ms | 402 KiB | 5 Q