diff --git a/admin/batch_manager_global.php b/admin/batch_manager_global.php
index 48b6ddced..4c4f8f74e 100644
--- a/admin/batch_manager_global.php
+++ b/admin/batch_manager_global.php
@@ -395,8 +395,7 @@ DELETE
   // synchronize metadata
   else if ('metadata' == $action)
   {
-    sync_metadata($collection);
-    $page['infos'][] = l10n('Metadata synchronized from file');
+    $page['infos'][] = l10n('Metadata synchronized from file').' <span class="badge">'.count($collection).'</span>';
   }
 
   else if ('delete_derivatives' == $action && !empty($_POST['del_derivatives_type']))
diff --git a/admin/themes/default/js/batchManagerGlobal.js b/admin/themes/default/js/batchManagerGlobal.js
index 8a593d9dd..88e8405fa 100644
--- a/admin/themes/default/js/batchManagerGlobal.js
+++ b/admin/themes/default/js/batchManagerGlobal.js
@@ -218,12 +218,81 @@ function selectDelDerivNone() {
 	$("#action_delete_derivatives input[type=checkbox]").prop("checked", false);
 }
 
-/* delete photos by blocks, with progress bar */
+/* sync metadatas or delete photos by blocks, with progress bar */
 jQuery('#applyAction').click(function(e) {
   if (typeof(elements) != "undefined") {
     return true;
   }
 
+  if (jQuery('[name="selectAction"]').val() == 'metadata') {
+    e.stopPropagation();
+    jQuery('.bulkAction').hide();
+    jQuery('#regenerationText').html(lang.syncProgressMessage);
+
+    elements = Array();
+
+    if (jQuery('input[name=setSelected]').is(':checked')) {
+      elements = all_elements;
+    }
+    else {
+      jQuery('input[name="selection[]"]').filter(':checked').each(function() {
+        elements.push(jQuery(this).val());
+      });
+    }
+
+    progressBar_max = elements.length;
+    var todo = 0;
+    var syncBlockSize = Math.min(
+      Number((elements.length/2).toFixed()),
+      1000
+    );
+    var image_ids = Array();
+
+    jQuery('#applyActionBlock').hide();
+    jQuery('select[name="selectAction"]').hide();
+    jQuery('#regenerationMsg').show();
+    jQuery('#progressBar').progressBar(0, {
+      max: progressBar_max,
+      textFormat: 'fraction',
+      boxImage: 'themes/default/images/progressbar.gif',
+      barImage: 'themes/default/images/progressbg_orange.gif'
+    });
+    for (i=0;i<elements.length;i++) {
+      image_ids.push(elements[i]);
+      if (i % syncBlockSize != syncBlockSize - 1 && i != elements.length - 1) {
+        continue;
+      }
+
+      (function(ids) {
+        var thisBatchSize = ids.length;
+        jQuery.ajax({
+          url: "ws.php?format=json&method=pwg.images.syncMetadata",
+          type:"POST",
+          dataType: "json",
+          data: {
+            pwg_token: jQuery("input[name=pwg_token").val(),
+            image_id: ids
+          },
+          success: function(data) {
+            todo += thisBatchSize;
+            var isOk = data.stat && "ok" == data.stat;
+            if (isOk && data.result.nb_synchronized != thisBatchSize)
+            /*TODO: user feedback only data.nb_synchronized images out of thisBatchSize were sync*/;
+            /*TODO: user feedback if isError*/
+            progressionBar(todo, progressBar_max, isOk);
+          },
+          error: function(data) {
+            todo += thisBatchSize;
+            /*TODO: user feedback*/
+            progressionBar(todo, progressBar_max, false);
+          }
+        });
+      } )(image_ids);
+
+      image_ids = Array();
+    }
+  }
+
   if (jQuery('[name="selectAction"]').val() == 'delete') {
     if (!jQuery("#action_delete input[name=confirm_deletion]").is(':checked')) {
       jQuery("#action_delete span.errors").show();
@@ -297,12 +366,12 @@ jQuery('#applyAction').click(function(e) {
           if (isOk && data.result != thisBatchSize)
             /*TODO: user feedback only data.result images out of thisBatchSize were deleted*/;
           /*TODO: user feedback if isError*/
-          progressDelete(todo, progressBar_max, isOk);
+          progressionBar(todo, progressBar_max, isOk);
         },
         error: function(data) {
           todo += thisBatchSize;
           /*TODO: user feedback*/
-          progressDelete(todo, progressBar_max, false);
+          progressionBar(todo, progressBar_max, false);
         }
       });
     } )(image_ids);
@@ -316,7 +385,7 @@ jQuery('#applyAction').click(function(e) {
   return false;
 });
 
-function progressDelete(val, max, success) {
+function progressionBar(val, max, success) {
   jQuery('#progressBar').progressBar(val, {
     max: max,
     textFormat: 'fraction',
@@ -333,14 +402,14 @@ jQuery("#action_delete input[name=confirm_deletion]").change(function() {
   jQuery("#action_delete span.errors").hide();
 });
 
-  jQuery('#sync_md5sum').click(function(e) {
-    jQuery(this).hide();
-    jQuery('#add_md5sum').show();
+jQuery('#sync_md5sum').click(function(e) {
+  jQuery(this).hide();
+  jQuery('#add_md5sum').show();
 
-    var addBlockSize = Math.min(
-      Number((jQuery('#md5sum_to_add').data('origin') / 2).toFixed()),
-      1000
-    );
+  var addBlockSize = Math.min(
+    Number((jQuery('#md5sum_to_add').data('origin') / 2).toFixed()),
+    1000
+  );
   add_md5sum_block(addBlockSize);
 
   return false;
diff --git a/admin/themes/default/template/batch_manager_global.tpl b/admin/themes/default/template/batch_manager_global.tpl
index 8397673bc..bbc9c7e28 100644
--- a/admin/themes/default/template/batch_manager_global.tpl
+++ b/admin/themes/default/template/batch_manager_global.tpl
@@ -22,6 +22,7 @@
 var lang = {
 	Cancel: '{'Cancel'|translate|escape:'javascript'}',
 	deleteProgressMessage: "{'Deletion in progress'|translate|escape:'javascript'}",
+	syncProgressMessage: "{'Synchronization in progress'|translate|escape:'javascript'}",
 	AreYouSure: "{'Are you sure?'|translate|escape:'javascript'}"
 };
 
diff --git a/admin/themes/default/theme.css b/admin/themes/default/theme.css
index 8559aa56a..261a74639 100644
--- a/admin/themes/default/theme.css
+++ b/admin/themes/default/theme.css
@@ -860,6 +860,15 @@ h2:lang(en) { text-transform:capitalize; }
   border-left:4px solid #00529b;
 }
 
+.badge {
+  background-color:#0a0;
+  color:white;
+  padding:1px 5px;
+  border-radius:10px;
+  -moz-border-radius:10px;
+  -webkit-border-radius:10px;
+  margin-left:5px;
+}
 
 .infos li, .errors li, .warnings li, .messages li { list-style-type:none; }
 .infos .submit {margin-left:30px;}
diff --git a/include/ws_functions/pwg.images.php b/include/ws_functions/pwg.images.php
index c141694a4..c49305164 100644
--- a/include/ws_functions/pwg.images.php
+++ b/include/ws_functions/pwg.images.php
@@ -1831,6 +1831,40 @@ function ws_images_setMd5sum($params, $service)
     );
 }
 
+/**
+ * API method
+ * Synchronize metadatas photos. Returns how many metadatas were sync.
+ * @param mixed[] $params
+ *    @option int image_id
+ */
+function ws_images_syncMetadata($params, $service)
+{
+  if (get_pwg_token() != $params['pwg_token'])
+  {
+    return new PwgError(403, 'Invalid security token');
+  }
+
+  $query = '
+SELECT id
+  FROM '.IMAGES_TABLE.'
+  WHERE id IN ('.implode(', ', $params['image_id']).')
+;';
+  $params['image_id'] = query2array($query, null, 'id');
+
+  if (empty($params['image_id']))
+  {
+    return new PwgError(403, 'No image found');
+  }
+
+  include_once(PHPWG_ROOT_PATH.'admin/include/functions_metadata.php');
+  include_once(PHPWG_ROOT_PATH.'admin/include/functions.php');
+  sync_metadata($params['image_id']);
+
+  return array(
+    'nb_synchronized' => count($params['image_id'])
+  );
+}
+
 /**
  * API method
  * Deletes orphan photos, by block. Returns how many orphans were deleted and how many are remaining.
diff --git a/language/en_UK/admin.lang.php b/language/en_UK/admin.lang.php
index 6028f3804..4f3882e3a 100644
--- a/language/en_UK/admin.lang.php
+++ b/language/en_UK/admin.lang.php
@@ -1014,3 +1014,4 @@ $lang['%d checksums were added'] = '%d checksums were added';
 $lang['With no checksum'] = 'With no checksum';
 $lang['Compute %d missing checksums'] = 'Compute %d missing checksums';
 $lang['checksums to add'] = 'checksums to add';
+$lang['Synchronization in progress'] = 'Synchronization in progress';
diff --git a/ws.php b/ws.php
index b0fcfdb3d..3c79803e3 100644
--- a/ws.php
+++ b/ws.php
@@ -510,17 +510,31 @@ function ws_addDefaultMethods( $arr )
       array('admin_only'=>true, 'post_only'=>true)
     );
 
-    $service->addMethod(
-        'pwg.images.setMd5sum',
-        'ws_images_setMd5sum',
-        array(
-          'block_size' => array('default'=>1000, 'type'=>WS_TYPE_INT|WS_TYPE_POSITIVE),
-          'pwg_token' =>  array(),
-          ),
-        'Set md5sum column, by blocks. Returns how many md5sums were added and how many are remaining.',
-        $ws_functions_root . 'pwg.images.php',
-        array('admin_only'=>true, 'post_only'=>true)
-      );
+  $service->addMethod(
+      'pwg.images.setMd5sum',
+      'ws_images_setMd5sum',
+      array(
+        'block_size' => array('default'=>1000, 'type'=>WS_TYPE_INT|WS_TYPE_POSITIVE),
+        'pwg_token' =>  array(),
+        ),
+      'Set md5sum column, by blocks. Returns how many md5sums were added and how many are remaining.',
+      $ws_functions_root . 'pwg.images.php',
+      array('admin_only'=>true, 'post_only'=>true)
+    );
+
+  $service->addMethod(
+      'pwg.images.syncMetadata',
+      'ws_images_syncMetadata',
+      array(
+        'image_id' => array('default'=>null,
+                            'type'=>WS_TYPE_ID|WS_TYPE_POSITIVE,
+                            'flags'=>WS_PARAM_FORCE_ARRAY),
+        'pwg_token' =>  array(),
+        ),
+      'Sync metadatas, by blocks. Returns how many images were synchronized',
+      $ws_functions_root . 'pwg.images.php',
+      array('admin_only'=>true, 'post_only'=>true)
+    );
 
   $service->addMethod(
       'pwg.images.deleteOrphans',