3v4l.org

run code in 500+ PHP versions simultaneously
<?php echo hash_hmac('sha256', 'Foo data', 'secret_key').PHP_EOL; echo hash_hmac('sha256', 'Foo data', '').PHP_EOL; echo hash_hmac('sha256', 'Foo data', null).PHP_EOL;

preferences:
19.17 ms | 474 KiB | 4 Q