- mb_strtolower: documentation ( source)
- strtolower: documentation ( source)
<?php
echo strtolower("This is an UTF-8 string, containing ÆØÅ ИЕ and will not be lowered")."\n";
echo mb_strtolower("This is an UTF-8 string, containing ÆØÅ ИЕ and will be lowered");