3v4l.org

run code in 200+ php & hhvm versions
<?php function base64_encode_url($string) { return str_replace(['+','/','='], ['-','_',''], base64_encode($string)); } function base64_decode_url($string) { return base64_decode(str_replace(['-','_'], ['+','/'], $string)); } for ($i=0; $i<20000; $i++) { $data = random_bytes(rand(12,20)); if (base64_decode_url(base64_encode($data)) !== $data) { echo "FAIL"; } } echo "OK";
based on 9TR6J