diff --git a/core/modules/image/config/schema/image.schema.yml b/core/modules/image/config/schema/image.schema.yml
index 4949fa3..110b755 100644
--- a/core/modules/image/config/schema/image.schema.yml
+++ b/core/modules/image/config/schema/image.schema.yml
@@ -131,6 +131,14 @@ field.formatter.settings.image:
       type: string
       label: 'Image style'
 
+field.formatter.settings.image_url:
+  type: mapping
+  label: 'Image URL format settings'
+  mapping:
+    image_style:
+      type: string
+      label: 'Image style'
+
 field.widget.settings.image_image:
   type: mapping
   label: 'Image field display format settings'
diff --git a/core/modules/image/src/Plugin/Field/FieldFormatter/ImageUrlFormatter.php b/core/modules/image/src/Plugin/Field/FieldFormatter/ImageUrlFormatter.php
index 1e07538..8902352 100644
--- a/core/modules/image/src/Plugin/Field/FieldFormatter/ImageUrlFormatter.php
+++ b/core/modules/image/src/Plugin/Field/FieldFormatter/ImageUrlFormatter.php
@@ -25,23 +25,31 @@
  */
 class ImageUrlFormatter extends ImageFormatter {
 
+  /**
+   * {@inheritdoc}
+   */
+  public static function defaultSettings() {
+    return [
+      'image_style' => '',
+    ];
+  }
 
   /**
    * {@inheritdoc}
    */
   public function settingsForm(array $form, FormStateInterface $form_state) {
     $image_styles = image_style_options(FALSE);
-    $element['image_style'] = array(
+    $element['image_style'] = [
       '#title' => t('Image style'),
       '#type' => 'select',
       '#default_value' => $this->getSetting('image_style'),
       '#empty_option' => t('None (original image)'),
       '#options' => $image_styles,
-      '#description' => array(
+      '#description' => [
         '#markup' => $this->linkGenerator->generate($this->t('Configure Image Styles'), new Url('entity.image_style.collection')),
         '#access' => $this->currentUser->hasPermission('administer image styles'),
-      ),
-    );
+      ],
+    ];
 
     return $element;
   }
@@ -49,8 +57,28 @@ public function settingsForm(array $form, FormStateInterface $form_state) {
   /**
    * {@inheritdoc}
    */
+  public function settingsSummary() {
+    $summary = [];
+
+    $image_styles = image_style_options(FALSE);
+    // Unset possible 'No defined styles' option.
+    unset($image_styles['']);
+    // Styles could be lost because of enabled/disabled modules that defines
+    // their styles in code.
+    $image_style_setting = $this->getSetting('image_style');
+    if (isset($image_styles[$image_style_setting])) {
+      $summary[] = t('Image style: @style', ['@style' => $image_styles[$image_style_setting]]);
+    }
+    else {
+      $summary[] = t('Original image');
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function viewElements(FieldItemListInterface $items) {
-    $elements = array();
+    $elements = [];
     $images = $this->getEntitiesToView($items);
 
     // Early opt-out if the field is empty.
@@ -64,12 +92,15 @@ public function viewElements(FieldItemListInterface $items) {
 
     // Collect cache tags to be added for each item in the field.
     $cache_tags = [];
+    /** @var \Drupal\image\Entity\ImageStyle|false $image_style */
+    $image_style = FALSE;
     if (!empty($image_style_setting)) {
       $image_style = $this->imageStyleStorage->load($image_style_setting);
       $cache_tags = $image_style->getCacheTags();
     }
 
     foreach ($images as $delta => $image) {
+      /** @var \Drupal\file\Entity\File $image */
       $image_uri = $image->getFileUri();
       $url = $image_style
         ? $image_style->buildUrl($image_uri)
@@ -77,12 +108,12 @@ public function viewElements(FieldItemListInterface $items) {
 
       $cache_tags = Cache::mergeTags($cache_tags, $image->getCacheTags());
 
-      $elements[$delta] = array(
+      $elements[$delta] = [
         '#markup' => $url,
-        '#cache' => array(
+        '#cache' => [
           'tags' => $cache_tags,
-        ),
-      );
+        ],
+      ];
     }
 
     return $elements;
diff --git a/core/modules/image/src/Tests/ImageFieldDisplayTest.php b/core/modules/image/src/Tests/ImageFieldDisplayTest.php
index 1e1d798..d539771 100644
--- a/core/modules/image/src/Tests/ImageFieldDisplayTest.php
+++ b/core/modules/image/src/Tests/ImageFieldDisplayTest.php
@@ -202,6 +202,26 @@ function _testImageFieldFormatters($scheme) {
       $this->drupalGet(ImageStyle::load('thumbnail')->buildUrl($image_uri));
       $this->assertResponse('403', 'Access denied to image style thumbnail as anonymous user.');
     }
+
+    // Test the image URL formatter without an image style.
+    $display_options = [
+      'type' => 'image_url',
+      'settings' => [],
+    ];
+
+    $expected_url = file_create_url($image_uri);
+    $this->assertEqual($expected_url, $node->{$field_name}->view($display_options)[0]['#markup']);
+
+    // Test the image URL formatter with an image style.
+    $display_options = [
+      'type' => 'image_url',
+      'settings' => [
+        'image_style' => 'thumbnail',
+      ],
+    ];
+
+    $expected_url = ImageStyle::load('thumbnail')->buildUrl($image_uri);
+    $this->assertEqual($expected_url, $node->{$field_name}->view($display_options)[0]['#markup']);
   }
 
   /**