How to submit form ajax in symfony2?

With jQuery, use serialize() the form and post it to your route.

$('#form').submit(function(e) {    e.preventDefault();    var url = "{{ path('YOUR_PATH') }}";    var formSerialize = $(this).serialize();        $.post(url, formSerialize, function(response) {        //your callback here        alert(response);    }, 'JSON');});

In your action

if ($form->isSubmitted() && $form->isValid()) {....  // or return new JsonResponse($anyData);  return new Response(json_encode(['status'=>'success']));}

it must be ok like this. but you can add some parameters like the format, methods etc... in your routing.

For the Ajax:

 $("#person").submit(function(e){    var formURL = "{{ path('form') }}";    var formData = new FormData(this);    $.ajax({        url: formURL,        type: 'POST',        data:  formData,        mimeType:"multipart/form-data",        contentType: false,        cache: false,        processData:false,        success: function(data, textStatus, jqXHR)        {        },        error: function(jqXHR, textStatus, errorThrown)        {        }    });    e.preventDefault(); //Prevent Default action.    e.unbind();});$("#person").submit();

And for Action

if ($request->isXmlHttpRequest()) {....    return new Response(json_encode(array('status'=>'success')));}