You need to add _token input in your form. Its for csrf protection.

<meta name="_token" content="{{ app('Illuminate\Encryption\Encrypter')->encrypt(csrf_token()) }}" />
<script type="text/javascript">
		$(function() {
			$.ajaxSetup({
				headers: {
					'X-XSRF-Token': $('meta[name="_token"]').attr('content')
				}
			});
		});
 	</script>

Add above code in your header and each ajax request will have csrf token by default. Also you need to specify _method for each request because laravel use PUT, PATCH methods that are not supported by default so you need to add another field

<input name="_method" value="PUT/PATCH" >

shah587 said:

You need to add _token input in your form. Its for csrf protection.

<meta name="_token" content="{{ app('Illuminate\Encryption\Encrypter')->encrypt(csrf_token()) }}" />
<script type="text/javascript">
  	$(function() {
  		$.ajaxSetup({
  			headers: {
  				'X-XSRF-Token': $('meta[name="_token"]').attr('content')
  			}
  		});
  	});
	</script>

Add above code in your header and each ajax request will have csrf token by default. Also you need to specify _method for each request because laravel use PUT, PATCH methods that are not supported by default so you need to add another field

<input name="_method" value="PUT/PATCH" >

i have changed my ajax handler to:

    <script>
    $(document).ready(function() {
        // Ajax for our form
        $('form.ajax').on('submit', function(event) {
            event.preventDefault();

            var formData = $(this).serialize(); // form data as string
            var formAction = $(this).attr('action'); // form handler url
            var formMethod = $(this).attr('method'); // GET, POST

            $.ajaxSetup({
                headers: {
                    'X-XSRF-Token': $('meta[name="_token"]').attr('content')
                }
            });

            $.ajax({
                type  : formMethod,
                url   : formAction,
                data  : formData,
                cache : false,

                beforeSend : function() {
                    console.log(formData);
                },

                success : function(data) {

                },

                error : function() {

                }
            });

            // console.log(formData);

            return false; // prevent send form
        });
    });
    </script>

added meta:

<meta name="_token" content="{{ app('Illuminate\Encryption\Encrypter')->encrypt(csrf_token()) }}" />

and hidden field with method name:

{!! Form::hidden('_method', 'PUT') !!}

and now error is: _token=SUIVMYuPYFqNxt9qrfm7iaX5DN4Sil38uJpV6CEj&ip=127.0.0.1&name=&email=&homepage=&message= jquery.min.js:4 POST http://laravel5-guestbook/guestbook 422 (Unprocessable Entity)jquery.min.js:4 sendjquery.min.js:4 m.extend.ajax(index):39 (anonymous function)jquery.min.js:3 m.event.dispatchjquery.min.js:3 r.handle

i think an issue somewhere in a verification CSRF token(according to http://stackoverflow.com/questions/27098239/).

Here is very simple example of Laravel 5 Ajax Form Submit example : https://hdtuto.com/article/php-laravel-ajax-form-submit-example

I hope it can help you... :)