Hello.

Normally Laravel return a JSON response for AJAX requests (but the client must specify it). To specify it from the client, just add the X-Requested-With header with the value XMLHttpRequest.

Something like this:

$.ajax
  ({
     type:"POST",
     beforeSend: function (request)
     {
         request.setRequestHeader('X-Requested-With', 'XMLHttpRequest');
    },
...
...

If you want to return a JSON or plain response all the time, just catch in your own way the Exception in the Exceptions/Handler.php file.

Something like this in the render method:

if($e instanceof NotFoundHttpException)
{
     return response()->json(['message' => 'Bad address', 'code' => 400], 400);
}

You can get detailed info and step by step course about this here: RESTful API with Laravel

Or something more general here: Laravel Course, step-by-step

Hope it helps. Best wishes.

Thank you, very useful.