<?php
header('Content-Type: text/html; charset=utf-8');
mb_internal_encoding('UTF-8');
?>
<meta charset="UTF-8">
$mysqli = new mysqli('localhost','user','pass','db');
$mysqli->set_charset('utf8mb4');
🎉
:
$bad = "🎉"; // mis-decoded bytes
$fixed = mb_convert_encoding($bad, 'UTF-8', 'ISO-8859-1'); // 🎉