Sometimes we need to remove some characters from strings to use they like slugs or for other usages, so two of the possible solutions are Transliterator $string = 'Ãéïòû';
$transliterator = Transliterator::createFromRules(':: Any-Latin; :: Latin-ASCII; :: NFD; :: [:Nonspacing Mark:] Remove; :: NFC;', Transliterator::FORWARD);
echo $normalized = $transliterator->transliterate($string); it will output: Aeiou