3v4l.org

run code in 300+ PHP versions simultaneously
<?php $user_id = 4; $result = rtrim(mcrypt_decrypt(MCRYPT_RIJNDAEL_256, "bite", base64_decode($user_id), MCRYPT_MODE_ECB), "\0"); var_dump($result);
preferences:
59.43 ms | 402 KiB | 5 Q