- var_dump: documentation ( source)
- urldecode: documentation ( source)
- htmlspecialchars_decode: documentation ( source)
<?php
$my = "i/7YHXEk1J8JidEsLuPzCsWWFW0=";
$received = "i\\/7YHXEk1J8JidEsLuPzCsWWFW0=";
var_dump(htmlspecialchars_decode(urldecode($received)), ENT_QUOTES);