diff --git a/core/modules/config/config.routing.yml b/core/modules/config/config.routing.yml
index f2a944a..36e6f89 100644
--- a/core/modules/config/config.routing.yml
+++ b/core/modules/config/config.routing.yml
@@ -54,3 +54,10 @@ config.export_single:
     config_name: NULL
   requirements:
     _permission: 'export configuration'
+
+config.snapshot_diff:
+  path: '/admin/config/development/configuration/sync/snapshot-diff/{storage}'
+  defaults:
+    _content: '\Drupal\config\Controller\ConfigController::snapshotDiff'
+  requirements:
+    _permission: 'import configuration'
diff --git a/core/modules/config/lib/Drupal/config/Controller/ConfigController.php b/core/modules/config/lib/Drupal/config/Controller/ConfigController.php
index dd7a0c3..c27a41b 100644
--- a/core/modules/config/lib/Drupal/config/Controller/ConfigController.php
+++ b/core/modules/config/lib/Drupal/config/Controller/ConfigController.php
@@ -10,16 +10,17 @@
 use Drupal\Component\Archiver\ArchiveTar;
 use Drupal\Core\Config\ConfigManagerInterface;
 use Drupal\Core\Config\StorageInterface;
-use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
 use Drupal\system\FileDownloadController;
 use Symfony\Component\Yaml\Dumper;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\Request;
+use Drupal\Core\Config\StorageComparer;
+use Drupal\Core\Controller\ControllerBase;
 
 /**
  * Returns responses for config module routes.
  */
-class ConfigController implements ContainerInjectionInterface {
+class ConfigController extends ControllerBase {
 
   /**
    * The target storage.
@@ -36,6 +37,13 @@ class ConfigController implements ContainerInjectionInterface {
   protected $sourceStorage;
 
   /**
+   * The snapshot.
+   *
+   * @var \Drupal\Core\Config\StorageInterface
+   */
+  protected $snapshotStorage;
+
+  /**
    * The configuration manager.
    *
    * @var \Drupal\Core\Config\ConfigManagerInterface
@@ -56,6 +64,7 @@ public static function create(ContainerInterface $container) {
     return new static(
       $container->get('config.storage'),
       $container->get('config.storage.staging'),
+      $container->get('config.storage.snapshot'),
       $container->get('config.manager'),
       new FileDownloadController()
     );
@@ -71,9 +80,10 @@ public static function create(ContainerInterface $container) {
    * @param \Drupal\system\FileDownloadController $file_download_controller
    *   The file download controller.
    */
-  public function __construct(StorageInterface $target_storage, StorageInterface $source_storage, ConfigManagerInterface $config_manager, FileDownloadController $file_download_controller) {
+  public function __construct(StorageInterface $target_storage, StorageInterface $source_storage, StorageInterface $snapshot_storage, ConfigManagerInterface $config_manager, FileDownloadController $file_download_controller) {
     $this->targetStorage = $target_storage;
     $this->sourceStorage = $source_storage;
+    $this->snapshotStorage = $snapshot_storage;
     $this->configManager = $config_manager;
     $this->fileDownloadController = $file_download_controller;
   }
@@ -134,9 +144,66 @@ public function diff($source_name, $target_name = NULL) {
         ),
       ),
       '#title' => "Back to 'Synchronize configuration' page.",
-      '#href' => 'admin/config/development/configuration',
+      '#route_name' => 'config.sync',
     );
 
     return $build;
   }
+
+  /**
+   * Show diff of snapshot and active/staging storage.
+   *
+   * @return string
+   *   Table showing a two-way diff between the snapshot and
+   *   active/staged configuration.
+   */
+  public function snapshotDiff($storage = 'active') {
+    $build = array();
+
+    // Add the CSS for the inline diff.
+    $build['#attached']['css'][] = drupal_get_path('module', 'system') . '/css/system.diff.css';
+
+    if ($storage == 'active') {
+      $build['#title'] = t('View changes between snapshot and active configuration.');
+      $used_storage = $this->targetStorage;
+      $compare_button = $this->l($this->t('Compare snapshot with staging storage'), 'config.snapshot_diff', array('storage' => 'staging'), array('attributes' => array('class' => array('button'))));
+    }
+    else {
+      $build['#title'] = t('View changes between snapshot and staging configuration.');
+      $used_storage = $this->sourceStorage;
+      $compare_button = $this->l($this->t('Compare snapshot with active storage'), 'config.snapshot_diff', array('storage' => 'active'), array('attributes' => array('class' => array('button'))));
+    }
+
+    $build['compare']['#markup'] = $compare_button;
+
+    $storage_snapshot_comparer = new StorageComparer($used_storage, $this->snapshotStorage);
+
+    // Collect changes.
+    $storage_snapshot_comparer->createChangelist();
+    $changelist = $storage_snapshot_comparer->getChangelist();
+
+    // Verify that we have an initial snapshot that matches the active/staging
+    // configuration.
+    if ($storage_snapshot_comparer->createChangelist()->hasChanges()) {
+      // Show changes for each configuration object.
+      foreach ($changelist as $op) {
+        foreach ($op as $name) {
+          $diff = $this->configManager->diff($this->snapshotStorage, $used_storage, $name);
+          $formatter = new \DrupalDiffFormatter();
+          $formatter->show_header = FALSE;
+          $build[$name] = array(
+            '#prefix' => '<h3>' . $name . '</h3>',
+            '#type' => 'table',
+            '#header' => array(
+              array('data' => t('Snapshot'), 'colspan' => '2'),
+              array('data' => ($storage == 'active') ? t('Active storage') : t('Staging storage'), 'colspan' => '2'),
+            ),
+            '#rows' => $formatter->format($diff),
+          );
+        }
+      }
+    }
+
+    return $build;
+  }
 }
diff --git a/core/modules/config/lib/Drupal/config/Form/ConfigImportForm.php b/core/modules/config/lib/Drupal/config/Form/ConfigImportForm.php
index ddbdca9..4ddb335 100644
--- a/core/modules/config/lib/Drupal/config/Form/ConfigImportForm.php
+++ b/core/modules/config/lib/Drupal/config/Form/ConfigImportForm.php
@@ -11,6 +11,7 @@
 use Drupal\Core\Form\FormBase;
 use Drupal\Component\Archiver\ArchiveTar;
 use Symfony\Component\DependencyInjection\ContainerInterface;
+use Drupal\Core\Config\StorageComparer;
 
 /**
  * Defines the configuration import form.
@@ -30,8 +31,10 @@ class ConfigImportForm extends FormBase {
    * @param \Drupal\Core\Config\StorageInterface $config_storage
    *   The configuration storage.
    */
-  public function __construct(StorageInterface $config_storage) {
+  public function __construct(StorageInterface $config_storage, StorageInterface $config_storage_snapshot, StorageInterface $config_storage_active) {
     $this->configStorage = $config_storage;
+    $this->configStorageSnapshot = $config_storage_snapshot;
+    $this->configStorageActive = $config_storage_active;
   }
 
   /**
@@ -39,7 +42,9 @@ public function __construct(StorageInterface $config_storage) {
    */
   public static function create(ContainerInterface $container) {
     return new static(
-      $container->get('config.storage.staging')
+      $container->get('config.storage.staging'),
+      $container->get('config.storage.snapshot'),
+      $container->get('config.storage')
     );
   }
 
@@ -54,6 +59,15 @@ public function getFormId() {
    * {@inheritdoc}
    */
   public function buildForm(array $form, array &$form_state) {
+    $active_snapshot_comparer = new StorageComparer($this->configStorageActive, $this->configStorageSnapshot);
+
+    // Verify that we have an initial snapshot that matches the active
+    // configuration.
+    if ($active_snapshot_comparer->createChangelist()->hasChanges()) {
+      drupal_set_message($this->t('Changes have been made to your active configuration, which might be lost on the next import attempt. You can find and review the differences between snapshot and active/staging storage here: <a href="@link">Compare snapshot and active/staging storage</a>.', array(
+        '@link' => $this->url('config.snapshot_diff', array('storage' => 'active')))), 'warning');
+    }
+
     $form['description'] = array(
       '#markup' => '<p>' . $this->t('Use the upload button below.') . '</p>',
     );
diff --git a/core/modules/config/lib/Drupal/config/Form/ConfigSync.php b/core/modules/config/lib/Drupal/config/Form/ConfigSync.php
index 19f417f..42d1c95 100644
--- a/core/modules/config/lib/Drupal/config/Form/ConfigSync.php
+++ b/core/modules/config/lib/Drupal/config/Form/ConfigSync.php
@@ -92,6 +92,13 @@ class ConfigSync extends FormBase {
   protected $themeHandler;
 
   /**
+   * The snapshot configuration object.
+   *
+   * @var \Drupal\Core\Config\StorageInterface
+   */
+  protected $snapshotStorage;
+
+  /**
    * Constructs the object.
    *
    * @param \Drupal\Core\Config\StorageInterface $sourceStorage
@@ -123,6 +130,7 @@ public function __construct(StorageInterface $sourceStorage, StorageInterface $t
     $this->typedConfigManager = $typed_config;
     $this->moduleHandler = $module_handler;
     $this->themeHandler = $theme_handler;
+    $this->snapshotStorage = $snapshotStorage;
   }
 
   /**
@@ -138,7 +146,8 @@ public static function create(ContainerInterface $container) {
       $container->get('url_generator'),
       $container->get('config.typed'),
       $container->get('module_handler'),
-      $container->get('theme_handler')
+      $container->get('theme_handler'),
+      $container->get('config.storage.snapshot')
     );
   }
 
@@ -153,6 +162,16 @@ public function getFormId() {
    * {@inheritdoc}
    */
   public function buildForm(array $form, array &$form_state) {
+    $active_snapshot_comparer = new StorageComparer($this->targetStorage, $this->snapshotStorage);
+
+    // Verify that we have an initial snapshot that matches the active
+    // configuration.
+    if ($active_snapshot_comparer->createChangelist()->hasChanges()) {
+      drupal_set_message($this->t('Changes have been made to your active configuration, which might be lost on the next import attempt. You can find and review the differences between snapshot and active/staging storage here: <a href="@link">Compare snapshot and active/staging storage</a>.', array(
+        '@link' => $this->url('config.snapshot_diff', array('storage' => 'active')))), 'warning');
+
+    }
+
     $form['actions'] = array('#type' => 'actions');
     $form['actions']['submit'] = array(
       '#type' => 'submit',