diff --git a/recaptcha.admin.inc b/recaptcha.admin.inc
index bd2dc23..b6c8452 100644
--- a/recaptcha.admin.inc
+++ b/recaptcha.admin.inc
@@ -62,10 +62,27 @@ function recaptcha_admin_settings() {
     '#options' => array(
       '' => t('Normal (default)'),
       'compact' => t('Compact'),
+      'invisible' => t('Invisible'),
     ),
     '#title' => t('Size'),
     '#type' => 'select',
   );
+  $form['recaptcha_widget_settings']['recaptcha_badge'] = array(
+    '#default_value' => variable_get('recaptcha_badge', 'bottomright'),
+    '#description' => t('Reposition the reCAPTCHA badge. "Inline" allows you to control the CSS.'),
+    '#options' => array(
+      'bottomright' => t('Bottom Right (default)'),
+      'bottomleft' => t('Bottom Left'),
+      'inline' => t('Inline'),
+    ),
+    '#title' => t('Badge'),
+    '#type' => 'select',
+    '#states' => array(
+      'visible' => array(
+        ':input[name="recaptcha_size"]' => array('value' => 'invisible'),
+      ),
+    ),
+  );
   $form['recaptcha_widget_settings']['recaptcha_tabindex'] = array(
     '#type' => 'textfield',
     '#title' => t('Tabindex'),
diff --git a/recaptcha.invisible.js b/recaptcha.invisible.js
new file mode 100644
index 0000000..309aa90
--- /dev/null
+++ b/recaptcha.invisible.js
@@ -0,0 +1,59 @@
+/**
+ * @file
+ * Invisible reCaptcha behaviors.
+ */
+
+/**
+ * ID of the form.
+ *
+ * @type {string}
+ */
+
+var submittedFormId = '';
+/**
+ * reCaptcha data-callback that submits the form.
+ *
+ * @param token
+ *   The validation token.
+ */
+function onInvisibleSubmit(token) {
+  document.getElementById(submittedFormId).submit();
+}
+
+(function ($) {
+  /**
+   * Handles the submission of the form with the invisible reCaptcha.
+   *
+   * @type {Drupal~behavior}
+   *
+   * @prop {Drupal~behaviorAttach} attach
+   *   Attaches the behavior for the invisible reCaptcha.
+   */
+
+  Drupal.behaviors.invisibleRecaptcha = {
+    attach: function(context, settings) {
+      $('form', context).each(function () {
+        var $form = $(this);
+
+        if ($form.find('.g-recaptcha[data-size="invisible"]').length) {
+          $form.find('input[type="submit"]').click(function (e) {
+            e.preventDefault();
+            validateInvisibleCaptcha($form);
+          });
+        }
+      });
+
+      /**
+       * Triggers the reCaptcha to validate the form.
+       *
+       * @param {jQuery} $form
+       *   The form object to be validated.
+      */
+      function validateInvisibleCaptcha($form) {
+       submittedFormId = $form.attr('id');
+        //grecaptcha.execute();
+          grecaptcha.execute(Drupal.behaviors.recaptcha.widgets[$('.g-recaptcha[data-size="invisible"]', $form).attr('id')]);
+      }
+    }
+  };
+})(jQuery);
\ No newline at end of file
diff --git a/recaptcha.js b/recaptcha.js
new file mode 100644
index 0000000..237cac0
--- /dev/null
+++ b/recaptcha.js
@@ -0,0 +1,17 @@
+(function ($, window, document) {
+    Drupal.behaviors.recaptcha = {
+        widgets: {},
+        attach: function (context, settings) {
+            // Check if the reCAPTCHA script is loaded yet. If not, don't worry: the
+            // onload callback recaptchaOnLoad() will make sure that this function is
+            // called again once grecaptcha is defined.
+            if (typeof grecaptcha == 'undefined') {
+                return;
+            }
+            $('.g-recaptcha', context).once('drupal-recaptcha').each(function () {
+                //grecaptcha.render(this, $(this).data());
+                Drupal.behaviors.recaptcha.widgets[this.id] = grecaptcha.render(this, $(this).data());
+            });
+        }
+    };
+})(jQuery, window, document);
\ No newline at end of file
diff --git a/recaptcha.module b/recaptcha.module
index 1e65aab..a79658e 100644
--- a/recaptcha.module
+++ b/recaptcha.module
@@ -11,6 +11,9 @@ require_once dirname(__FILE__) . '/recaptcha-php/src/ReCaptcha/RequestParameters
 require_once dirname(__FILE__) . '/recaptcha-php/src/ReCaptcha/Response.php';
 require_once dirname(__FILE__) . '/src/ReCaptcha/RequestMethod/Drupal7Post.php';
 
+use \ReCaptcha\ReCaptcha;
+use \ReCaptcha\RequestMethod;
+
 /**
  * Implements hook_help().
  */
@@ -68,7 +71,7 @@ function recaptcha_permission() {
 /**
  * Implements hook_captcha().
  */
-function recaptcha_captcha($op, $captcha_type = '') {
+function recaptcha_captcha($op, $captcha_type = '', $captcha_sid = '') {
   global $language;
 
   switch ($op) {
@@ -101,6 +104,7 @@ function recaptcha_captcha($op, $captcha_type = '') {
           }
 
           $attributes = array(
+            'id' => 'g-recaptcha' . $captcha_sid,
             'class' => 'g-recaptcha',
             'data-sitekey' => $recaptcha_site_key,
             'data-theme' => variable_get('recaptcha_theme', 'light'),
@@ -108,21 +112,67 @@ function recaptcha_captcha($op, $captcha_type = '') {
             'data-size' => variable_get('recaptcha_size', ''),
             'data-tabindex' => variable_get('recaptcha_tabindex', 0),
           );
+
+          if (variable_get('recaptcha_size', '') == 'invisible') {
+            $attributes['data-callback'] = 'onInvisibleSubmit';
+            $attributes['data-badge'] = variable_get('recaptcha_badge', 'bottomright');
+
+            $captcha['form']['#attached']['js'] = array(
+              drupal_get_path('module', 'recaptcha') . '/recaptcha.invisible.js',
+            );
+          }
+
           // Filter out empty tabindex/size.
           $attributes = array_filter($attributes);
 
           $captcha['form']['recaptcha_widget'] = array(
             '#markup' => '<div' . drupal_attributes($attributes) . '></div>',
             '#suffix' => $noscript,
+            '#attached' => array(
+              'js' => array(
+                drupal_get_path('module', 'recaptcha') . '/recaptcha.js',
+              ),
+            ),
           );
 
-          // @todo: #1664602: D7 does not yet support "async" in drupal_add_js().
-          // drupal_add_js(url('https://www.google.com/recaptcha/api.js', array('query' => array('hl' => $language->language), 'absolute' => TRUE)), array('defer' => TRUE, 'async' => TRUE, 'type' => 'external'));
+          // The reCAPTHCHA onload callback must be defined before the
+          // reCAPTHCHA script itself is loaded. Since the reCAPTHCHA script is
+          // currently added with drupal_add_html_head(), we must do the same
+          // here so we can control the ordering of the script tags in <head>.
+          // The recaptchaOnLoad() function tries to initialize the recaptcha's
+          // on the page. If the Drupal behavior is not available yet, don't
+          // worry: Drupal's attachBehaviors() will take care of it later.
+          $onload_js = <<<JS
+function recaptchaOnLoad() {
+  if (typeof Drupal.behaviors.recaptcha.attach != 'undefined') {
+   Drupal.behaviors.recaptcha.attach();
+  }
+};
+JS;
+          $data = array(
+            '#tag' => 'script',
+            '#value' => $onload_js,
+            '#weight' => -1,
+          );
+          drupal_add_html_head($data, 'recaptcha_onload');
+
+          /*
+          @todo: #1664602: D7 does not yet support "async" in drupal_add_js().
+          drupal_add_js(url('https://www.google.com/recaptcha/api.js', array('query' => array('hl' => $language->language), 'absolute' => TRUE)), array('defer' => TRUE, 'async' => TRUE, 'type' => 'external'));
+          */
           $data = array(
             '#tag' => 'script',
             '#value' => '',
+            '#weight' => 0,
             '#attributes' => array(
-              'src' => url('https://www.google.com/recaptcha/api.js', array('query' => array('hl' => $language->language), 'absolute' => TRUE)),
+              'src' => url('https://www.google.com/recaptcha/api.js', array(
+                'absolute' => TRUE,
+                'query' => array(
+                  'hl' => $language->language,
+                  'onload' => 'recaptchaOnLoad',
+                  'render' => 'explicit',
+                ),
+              )),
               'async' => 'async',
               'defer' => 'defer',
             ),
@@ -187,5 +237,11 @@ function recaptcha_captcha_validation($solution, $response, $element, $form_stat
 function template_preprocess_recaptcha_widget_noscript(&$variables) {
   $variables['sitekey']  = check_plain($variables['widget']['sitekey']);
   $variables['language'] = check_plain($variables['widget']['language']);
-  $variables['url']      = check_url(url('https://www.google.com/recaptcha/api/fallback', array('query' => array('k' => $variables['widget']['sitekey'], 'hl' => $variables['widget']['language']), 'absolute' => TRUE)));
+  $variables['url']      = check_url(url('https://www.google.com/recaptcha/api/fallback', array(
+    'query' => array(
+      'k' => $variables['widget']['sitekey'],
+      'hl' => $variables['widget']['language']
+    ),
+    'absolute' => TRUE
+  )));
 }
diff --git a/recaptcha.test b/recaptcha.test
index 4afedf7..3e8c1fc 100644
--- a/recaptcha.test
+++ b/recaptcha.test
@@ -4,6 +4,10 @@
  * @file
  * Tests for reCAPTCHA module.
  */
+
+/**
+ * Helper class for ReCaptcha test cases.
+ */
 class ReCaptchaBasicTest extends DrupalWebTestCase {
 
   /**
@@ -21,7 +25,7 @@ class ReCaptchaBasicTest extends DrupalWebTestCase {
   /**
    * {@inheritdoc}
    */
-  function setUp() {
+  public function setUp() {
     parent::setUp('captcha', 'recaptcha');
     module_load_include('inc', 'captcha');
 
@@ -45,7 +49,7 @@ class ReCaptchaBasicTest extends DrupalWebTestCase {
   /**
    * Test access to the administration page.
    */
-  function testReCaptchaAdminAccess() {
+  public function testReCaptchaAdminAccess() {
     $this->drupalLogin($this->admin_user);
     $this->drupalGet('admin/config/people/captcha/recaptcha');
     $this->assertNoText(t('Access denied'), 'Admin users should be able to access the reCAPTCHA admin page', 'reCAPTCHA');
@@ -55,7 +59,7 @@ class ReCaptchaBasicTest extends DrupalWebTestCase {
   /**
    * Test the reCAPTCHA settings form.
    */
-  function testReCaptchaAdminSettingsForm() {
+  public function testReCaptchaAdminSettingsForm() {
     $this->drupalLogin($this->admin_user);
 
     $site_key = $this->randomName(40);
@@ -88,7 +92,7 @@ class ReCaptchaBasicTest extends DrupalWebTestCase {
   /**
    * Testing the protection of the user login form.
    */
-  function testReCaptchaOnLoginForm() {
+  public function testReCaptchaOnLoginForm() {
     global $language;
 
     $site_key = $this->randomName(40);;
@@ -127,13 +131,17 @@ class ReCaptchaBasicTest extends DrupalWebTestCase {
 
     // Check if there is a reCAPTCHA on the login form.
     $this->drupalGet('user');
-    $this->assertRaw($grecaptcha, '[testReCaptchaOnLoginForm]: reCAPTCHA is shown on form.');
-    $this->assertRaw('<script src="https://www.google.com/recaptcha/api.js?hl=' . $language->language . '" async="async" defer="defer"></script>', '[testReCaptchaOnLoginForm]: reCAPTCHA is shown on form.');
+    $captcha_sid = $this->getCaptchaSid();
+    $grecaptcha = '<div id="g-recaptcha' . $captcha_sid . '" class="g-recaptcha" data-sitekey="' . $site_key . '" data-theme="light" data-type="image"></div>';
+    $this->assertRaw($grecaptcha, '[testReCaptchaOnLoginForm]: reCAPTCHA is shown on form.' . $grecaptcha);
+    $this->assertRaw('<script src="https://www.google.com/recaptcha/api.js?hl=' . $language->language . '&amp;onload=recaptchaOnLoad&amp;render=explicit" async="async" defer="defer"></script>', '[testReCaptchaOnLoginForm]: reCAPTCHA API script is present.');
     $this->assertNoRaw($grecaptcha . '<noscript>', '[testReCaptchaOnLoginForm]: NoScript code is not enabled for the reCAPTCHA.');
 
     // Test if the fall back url is properly build and noscript code added.
     variable_set('recaptcha_noscript', 1);
     $this->drupalGet('user');
+    $captcha_sid = $this->getCaptchaSid();
+    $grecaptcha = '<div id="g-recaptcha' . $captcha_sid . '" class="g-recaptcha" data-sitekey="' . $site_key . '" data-theme="light" data-type="image"></div>';
     $this->assertRaw($grecaptcha . '<noscript>', '[testReCaptchaOnLoginForm]: NoScript for reCAPTCHA is shown on form.');
     $this->assertRaw('https://www.google.com/recaptcha/api/fallback?k=' . $site_key . '&amp;hl=' . $language->language, '[testReCaptchaOnLoginForm]: Fallback URL with IFRAME has been found.');
 
@@ -170,10 +178,19 @@ class ReCaptchaBasicTest extends DrupalWebTestCase {
     // Check for error message.
     $this->assertText(t('The answer you entered for the CAPTCHA was not correct.'), 'CAPTCHA should block user login form', 'reCAPTCHA');
 
-    // And make sure that user is not logged in: check for name and password fields on ?q=user
+    // And make sure that user is not logged in: check for name and password fields on ?q=user.
     $this->drupalGet('user');
     $this->assertField('name', t('Username field found.'), 'reCAPTCHA');
     $this->assertField('pass', t('Password field found.'), 'reCAPTCHA');
   }
 
+  /**
+   * Get captcha_sid.
+   */
+  protected function getCaptchaSid() {
+    $elements = $this->xpath('//input[@name="captcha_sid"]');
+    $captcha_sid = (int) $elements[0]['value'];
+    return $captcha_sid;
+  }
+
 }