How to decode Unicode escape sequences like "\u00ed" to proper UTF-8 encoded characters?
Try this:
$str = preg_replace_callback('/\\\\u([0-9a-fA-F]{4})/', function ($match) { return mb_convert_encoding(pack('H*', $match[1]), 'UTF-8', 'UCS-2BE');}, $str);In case it's UTF-16 based C/C++/Java/Json-style:
$str = preg_replace_callback('/\\\\u([0-9a-fA-F]{4})/', function ($match) { return mb_convert_encoding(pack('H*', $match[1]), 'UTF-8', 'UTF-16BE');}, $str);