use laravel validation rules on client side.

form

<div class="form-group">
  {{Form::label('label','text')}}
  {{Form::text('name',$value,['class'=>'form-control lara-validation' , 'data-lara-key' => 'email','data-lara-rules' => 'required|email'])}}
  <div class="lara-validation-note"></div>
</div>

routes.php

Route::any('/validate', function () {
    $rule = Input::get('rule');
    $key = Input::get('key');
    $value = Input::get('value');
    $v = Validator::make([$key => $value], [$key => $rule]);
    $data = $v->fails() ? ['hasError' => true, 'msg' => $v->messages()->first()] : ['hasError' => false, 'msg' => 'ok'];
    return Response::json($data);
});

validation.js

$(document).on('change paste', '.lara-validation', function() {
    var el = $(this);
    var val = el.val();
    var key = el.data('laraKey');
    var rule = el.data('laraRules');
    $.ajax({
        type: 'POST',
        url: '/validate',
        dataType: 'json',
        data: {
            rule: rule,
            key: key,
            value: val
        },
        success: function(data) {
            if (data.hasError) {
                el.parent('.form-group').addClass('has-error');
                el.siblings('.lara-note').text('').text(data.msg);
            } else {
                el.parent('.form-group').removeClass('has-error').addClass('has-success');
                el.siblings('.lara-note').text('');
            }
        }
    });
});