3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php echo mb_strlen("\xF4\x8F\xBF\xBF\xF4\x8F\xBF\xBF\xF4\x8F\xBF\xBF", 'UTF-8');
based on 50mnv
Output for 4.3.0 - 7.2.0
3