While you’re usually fine without it, you can and should set the
<?php $data = /** whatever you're serializing **/; header('Content-Type: application/json; charset=utf-8'); echo json_encode($data);
If I’m not using a particular framework, I usually allow some request params to modify the output behavior. It can be useful, generally for quick troubleshooting, to not send a header, or sometimes
print_r the data payload to eyeball it (though in most cases, it shouldn’t be necessary).