diff -u b/core/core.api.php b/core/core.api.php
--- b/core/core.api.php
+++ b/core/core.api.php
@@ -2079,6 +2079,13 @@
  *   - message: Translated message to display.
  *   - url: For a bar progress indicator, URL path for determining progress.
  *   - interval: For a bar progress indicator, how often to update it.
+ * - url: A \Drupal\Core\URL to which to submit the Ajax request. If omitted,
+ *   defaults to either the same URL as the form or link destination is for
+ *   someone with JavaScript disabled, or a slightly modified version (e.g.,
+ *   with a query parameter added, removed, or changed) of that URL if
+ *   necessary to support Drupal's content negotiation. It is recommended to
+ *   omit this key and use Drupal's content negotiation rather than using
+ *   substantially different URLs between Ajax and non-Ajax.
  *
  * @subsection sub_callback Setting up a callback to process Ajax
  * Once you have set up your form to trigger an Ajax response (see @ref sub_form
reverted:
--- b/core/includes/pager.inc
+++ a/core/includes/pager.inc
@@ -148,12 +148,7 @@
 function pager_get_query_parameters() {
   $query = &drupal_static(__FUNCTION__);
   if (!isset($query)) {
+    $query = UrlHelper::filterQueryParameters(\Drupal::request()->query->all(), array('page'));
-    // There is a chance that the pager is rendered in the context of an AJAX
-    // form request. Therefore exclude AJAX_FORM_REQUEST from from the query
-    // arguments, as otherwise clicking the link would be interpreted
-    // potentially as an AJAX form request, especially when done as POST request
-    // using JS.
-    $query = UrlHelper::filterQueryParameters(\Drupal::request()->query->all(), array('page', \Drupal\Core\Form\FormBuilderInterface::AJAX_FORM_REQUEST));
   }
   return $query;
 }
diff -u b/core/lib/Drupal/Core/Render/Element/RenderElement.php b/core/lib/Drupal/Core/Render/Element/RenderElement.php
--- b/core/lib/Drupal/Core/Render/Element/RenderElement.php
+++ b/core/lib/Drupal/Core/Render/Element/RenderElement.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\Core\Render\Element;
 
-use Drupal\Component\Utility\NestedArray;
 use Drupal\Core\Form\FormBuilderInterface;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Plugin\PluginBase;
@@ -143,6 +142,7 @@
    *   Properties used:
    *   - #ajax['event']
    *   - #ajax['prevent']
+   *   - #ajax['url']
    *   - #ajax['callback']
    *   - #ajax['options']
    *   - #ajax['wrapper']
@@ -152,9 +152,6 @@
    *
    * @return array
    *   The processed element with the necessary JavaScript attached to it.
-   *
-   * @throws \InvalidArgumentException
-   *   Thrown when an element provides a custom #ajax URL.
    */
   public static function preRenderAjaxForm($element) {
     // Skip already processed elements.
@@ -169,12 +166,6 @@
       return $element;
     }
 
-    // If #ajax is TRUE, convert it to an empty array. Depending on the #type,
-    // it will still be given an event.
-    if ($element['#ajax'] === TRUE) {
-      $element['#ajax'] = [];
-    }
-
     // Add a reasonable default event handler if none was specified.
     if (isset($element['#ajax']) && !isset($element['#ajax']['event'])) {
       switch ($element['#type']) {
@@ -233,23 +224,26 @@
 
       $settings = $element['#ajax'];
 
-      // Assign default settings.
+      // Assign default settings. When 'url' is set to NULL, ajax.js submits the
+      // Ajax request to the same URL as the form or link destination is for
+      // someone with JavaScript disabled. This is generally preferred as a way to
+      // ensure consistent server processing for js and no-js users, and Drupal's
+      // content negotiation takes care of formatting the response appropriately.
+      // However, 'url' and 'options' may be set when wanting server processing
+      // to be substantially different for a JavaScript triggered submission.
       $settings += [
+        'url' => NULL,
+        'options' => ['query' => []],
         'dialogType' => 'ajax',
       ];
-      if (array_key_exists('callback', $settings)) {
+      if (array_key_exists('callback', $settings) && !isset($settings['url'])) {
+        $settings['url'] = Url::fromRoute('<current>');
         // Add all the current query parameters in order to ensure that we build
         // the same form on the AJAX POST requests. For example,
         // \Drupal\user\AccountForm takes query parameters into account in order
         // to hide the password field dynamically.
-        $query = \Drupal::request()->query->all();
-        $query[FormBuilderInterface::AJAX_FORM_REQUEST] = TRUE;
-
-        // Add options['query'] => [] as default value.
-        $settings = NestedArray::mergeDeep($settings, ['options' => ['query' => []]]);
-        $options['query'] = $settings['options']['query'] + $query;
-
-        $settings['url'] = Url::fromRoute('<current>', [], $options)->toString();
+        $settings['options']['query'] += \Drupal::request()->query->all();
+        $settings['options']['query'][FormBuilderInterface::AJAX_FORM_REQUEST] = TRUE;
       }
 
       // @todo Legacy support. Remove in Drupal 8.
@@ -257,6 +251,13 @@
         $settings['method'] = 'replaceWith';
       }
 
+      // Convert \Drupal\Core\Url object to string.
+      if (isset($settings['url']) && $settings['url'] instanceof Url) {
+        $settings['url'] = $settings['url']->setOptions($settings['options'])->toString();
+      }
+      else {
+        $settings['url'] = NULL;
+      }
       unset($settings['options']);
 
       // Add special data to $settings['submit'] so that when this element
reverted:
--- b/core/modules/views/src/Plugin/views/field/Field.php
+++ a/core/modules/views/src/Plugin/views/field/Field.php
@@ -447,7 +447,9 @@
       '#title' => $this->t('Formatter'),
       '#options' => $formatters,
       '#default_value' => $this->options['type'],
+      '#ajax' => array(
+        'url' => views_ui_build_form_url($form_state),
+      ),
-      '#ajax' => TRUE,
       '#submit' => array(array($this, 'submitTemporaryForm')),
       '#executes_submit_callback' => TRUE,
     );
reverted:
--- b/core/modules/views_ui/src/Form/Ajax/ConfigHandler.php
+++ a/core/modules/views_ui/src/Form/Ajax/ConfigHandler.php
@@ -181,7 +181,9 @@
         '#value' => $this->t('Remove'),
         '#submit' => array(array($this, 'remove')),
         '#limit_validation_errors' => array(array('override')),
+        '#ajax' => array(
+          'url' => Url::fromRoute('<current>'),
+        ),
-        '#ajax' => TRUE,
         '#button_type' => 'danger',
       );
     }
reverted:
--- b/core/modules/views_ui/src/Form/Ajax/RearrangeFilter.php
+++ a/core/modules/views_ui/src/Form/Ajax/RearrangeFilter.php
@@ -134,7 +134,7 @@
             'class' => array('views-remove-group'),
           ),
           '#group' => $id,
+          '#ajax' => ['url' => NULL],
-          '#ajax' => TRUE,
         );
       }
       $group_options[$id] = $id == 1 ? $this->t('Default group') : $this->t('Group @group', array('@group' => $id));
@@ -218,7 +218,7 @@
       '#attributes' => array(
         'class' => array('views-add-group'),
       ),
+      '#ajax' => ['url' => NULL],
-      '#ajax' => TRUE,
     );
 
     return $form;
reverted:
--- b/core/modules/views_ui/src/Tests/PreviewTest.php
+++ a/core/modules/views_ui/src/Tests/PreviewTest.php
@@ -278,7 +278,7 @@
    * @param int $row_count
    *   The expected number of rows in the preview.
    */
+  protected function assertPreviewAJAX($result, $row_count) {
-  protected function assertPreviewAJAX(array $result, $row_count) {
     // Has AJAX callback replied with an insert command? If so, we can
     // assume that the page content was updated with AJAX returned data.
     $result_commands = array();
reverted:
--- b/core/modules/views_ui/src/ViewPreviewForm.php
+++ a/core/modules/views_ui/src/ViewPreviewForm.php
@@ -76,6 +76,7 @@
    * {@inheritdoc}
    */
   protected function actions(array $form, FormStateInterface $form_state) {
+    $view = $this->entity;
     return array(
       '#attributes' => array(
         'id' => 'preview-submit-wrapper',
@@ -88,7 +89,7 @@
         '#submit' => array('::submitPreview'),
         '#id' => 'preview-submit',
         '#ajax' => array(
+          'url' => Url::fromRoute('entity.view.preview_form', ['view' => $view->id(), 'display_id' => $this->displayID]),
-          'callback' => [get_called_class(), 'previewSubmit'],
           'wrapper' => 'views-preview-wrapper',
           'event' => 'click',
           'progress' => array('type' => 'fullscreen'),
@@ -99,19 +100,6 @@
   }
 
   /**
-   * AJAX callback: Return the form as-is to let the views UI be rebuilt.
-   *
-   * @param array $form
-   *   An associative array containing the structure of the form.
-   *
-   * @return array
-   *   The form, with no changes.
-   */
-  public static function previewSubmit(array $form) {
-    return $form;
-  }
-
-  /**
    * Form submission handler for the Preview button.
    */
   public function submitPreview($form, FormStateInterface $form_state) {
reverted:
--- b/core/modules/views_ui/src/ViewUI.php
+++ a/core/modules/views_ui/src/ViewUI.php
@@ -12,9 +12,7 @@
 use Drupal\Component\Utility\Xss;
 use Drupal\Core\Config\Entity\ThirdPartySettingsInterface;
 use Drupal\Core\EventSubscriber\AjaxResponseSubscriber;
-use Drupal\Core\Form\FormBuilderInterface;
 use Drupal\Core\Form\FormStateInterface;
-use Drupal\Core\Render\BubbleableMetadata;
 use Drupal\Core\Url;
 use Drupal\views\Views;
 use Drupal\Core\Entity\EntityStorageInterface;
@@ -313,6 +311,11 @@
       $names = array(t('Apply'), t('Apply and continue'));
     }
 
+    // Views provides its own custom handling of AJAX form submissions. Usually
+    // this happens at the same path, but custom paths may be specified in
+    // $form_state.
+    $form_url = $form_state->get('url') ?: Url::fromRouteMatch(\Drupal::routeMatch());
+
     // Forms that are purely informational set an ok_button flag, so we know not
     // to create an "Apply" button for them.
     if (!$form_state->get('ok_button')) {
@@ -327,7 +330,9 @@
         // take care of running the regular submit handler as appropriate.
         '#submit' => array(array($this, 'standardSubmit')),
         '#button_type' => 'primary',
+        '#ajax' => array(
+          'url' => $form_url,
+        ),
-        '#ajax' => TRUE,
       );
       // Form API button click detection requires the button's #value to be the
       // same between the form build of the initial page request, and the
@@ -353,7 +358,9 @@
       '#value' => !$form_state->get('ok_button') ? t('Cancel') : t('Ok'),
       '#submit' => array($cancel_submit),
       '#validate' => array(),
+      '#ajax' => array(
+        'path' => $form_url,
+      ),
-      '#ajax' => TRUE,
       '#limit_validation_errors' => array(),
     );
 
@@ -543,10 +550,6 @@
     $request_stack = \Drupal::requestStack();
     $current_request = $request_stack->getCurrentRequest();
     $executable = $this->getExecutable();
-    /** @var \Drupal\Core\Render\RendererInterface $renderer */
-    $renderer = \Drupal::service('renderer');
-    /** @var \Drupal\Core\Render\RenderCacheInterface $render_cache */
-    $render_cache = \Drupal::service('render_cache');
 
     // Determine where the query and performance statistics should be output.
     $config = \Drupal::config('views.settings');
@@ -575,7 +578,7 @@
       // have some input in the query parameters, so we merge request() and
       // query() to ensure we get it all.
       $exposed_input = array_merge(\Drupal::request()->request->all(), \Drupal::request()->query->all());
+      foreach (array('view_name', 'view_display_id', 'view_args', 'view_path', 'view_dom_id', 'pager_element', 'view_base_path', AjaxResponseSubscriber::AJAX_REQUEST_PARAMETER, 'ajax_page_state', 'form_id', 'form_build_id', 'form_token') as $key) {
-      foreach (array('view_name', 'view_display_id', 'view_args', 'view_path', 'view_dom_id', 'pager_element', 'view_base_path', FormBuilderInterface::AJAX_FORM_REQUEST, AjaxResponseSubscriber::AJAX_REQUEST_PARAMETER, 'ajax_page_state', 'form_id', 'form_build_id', 'form_token') as $key) {
         if (isset($exposed_input[$key])) {
           unset($exposed_input[$key]);
         }
@@ -609,13 +612,10 @@
       $raw_parameters->set('display_id', $display_id);
       $request->attributes->set('_raw_variables', $raw_parameters);
 
-      $request->query->remove(FormBuilderInterface::AJAX_FORM_REQUEST);
-
       foreach ($args as $key => $arg) {
         $request->attributes->set('arg_' . $key, $arg);
       }
       $request_stack->push($request);
-      $executable->setRequest($request_stack->getCurrentRequest());
 
       // Suppress contextual links of entities within the result set during a
       // Preview.
@@ -855,14 +855,6 @@
       ];
     }
 
-    if (!empty($output['preview'])) {
-      // We render the preview now, in order to render it in the context of the
-      // previous setup request, because for example pager links depend on the
-      // "current" URL.
-      $renderer->renderPlain($output['preview']);
-      $output['preview'] = $render_cache->getCacheableRenderArray($output['preview']);
-    }
-
     // Ensure that we just remove an additional request we pushed earlier.
     // This could happen if $errors was not empty.
     if ($request_stack->getCurrentRequest() != $current_request) {
diff -u b/core/tests/Drupal/Tests/Core/Render/Element/RenderElementTest.php b/core/tests/Drupal/Tests/Core/Render/Element/RenderElementTest.php
--- b/core/tests/Drupal/Tests/Core/Render/Element/RenderElementTest.php
+++ b/core/tests/Drupal/Tests/Core/Render/Element/RenderElementTest.php
@@ -115,22 +115,2 @@
 
-  /**
-   * @covers ::preRenderAjaxForm
-   */
-  public function testPreRenderAjaxFormAjaxTrue() {
-    $element = [
-      '#type' => 'select',
-      '#id' => 'test',
-      '#ajax' => TRUE,
-    ];
-
-    $element = RenderElement::preRenderAjaxForm($element);
-
-    $this->assertTrue($element['#ajax_processed']);
-    $ajax_settings = [
-      'event' => 'change',
-      'dialogType' => 'ajax',
-    ];
-    $this->assertSame($ajax_settings, $element['#attached']['drupalSettings']['ajax']['test']);
-  }
-
 }