diff --git a/map/framework.cpp b/map/framework.cpp
index 5e72dd6139..ea56f94e96 100644
--- a/map/framework.cpp
+++ b/map/framework.cpp
@@ -3313,11 +3313,12 @@ void Framework::UploadUGC(User::CompleteUploadingHandler const & onCompleteUploa
     return;
   }
 
-  m_ugcApi->GetUGCToSend([this, onCompleteUploading](string && json)
+  m_ugcApi->GetUGCToSend([this, onCompleteUploading](string && json, size_t numberOfUnsynchronized)
   {
     if (!json.empty())
     {
-      m_user.UploadUserReviews(std::move(json), [this, onCompleteUploading](bool isSuccessful)
+      m_user.UploadUserReviews(std::move(json), numberOfUnsynchronized,
+                               [this, onCompleteUploading](bool isSuccessful)
       {
         if (onCompleteUploading != nullptr)
           onCompleteUploading(isSuccessful);
diff --git a/map/user.cpp b/map/user.cpp
index 7db4a25a39..a269c01f58 100644
--- a/map/user.cpp
+++ b/map/user.cpp
@@ -313,7 +313,7 @@ void User::RequestUserDetails()
   });
 }
 
-void User::UploadUserReviews(std::string && dataStr,
+void User::UploadUserReviews(std::string && dataStr, size_t numberOfUnsynchronized,
                              CompleteUploadingHandler const & onCompleteUploading)
 {
   std::string const url = ReviewReceiverUrl();
@@ -326,7 +326,8 @@ void User::UploadUserReviews(std::string && dataStr,
   if (m_accessToken.empty())
     return;
 
-  GetPlatform().RunTask(Platform::Thread::Network, [this, url, dataStr, onCompleteUploading]()
+  GetPlatform().RunTask(Platform::Thread::Network,
+                        [this, url, dataStr, numberOfUnsynchronized, onCompleteUploading]()
   {
     size_t const bytesCount = dataStr.size();
     Request(url, [this, dataStr](platform::HttpClient & request)
@@ -343,10 +344,11 @@ void User::UploadUserReviews(std::string && dataStr,
       if (onCompleteUploading != nullptr)
         onCompleteUploading(true /* isSuccessful */);
     },
-    [this, onCompleteUploading](int errorCode)
+    [this, onCompleteUploading, numberOfUnsynchronized](int errorCode)
     {
       alohalytics::Stats::Instance().LogEvent("UGC_DataUpload_error",
-                                              strings::to_string(errorCode));
+                                              {{"error", strings::to_string(errorCode)},
+                                               {"num", strings::to_string(numberOfUnsynchronized)}});
       LOG(LWARNING, ("Reviews have not been uploaded. Code =", errorCode));
 
       if (onCompleteUploading != nullptr)
diff --git a/map/user.hpp b/map/user.hpp
index 04639142f6..ab82b6bfc2 100644
--- a/map/user.hpp
+++ b/map/user.hpp
@@ -60,7 +60,7 @@ public:
   std::string GetAccessToken() const;
   Details GetDetails() const;
 
-  void UploadUserReviews(std::string && dataStr,
+  void UploadUserReviews(std::string && dataStr, size_t numberOfUnsynchronized,
                          CompleteUploadingHandler const & onCompleteUploading);
 
 private:
diff --git a/ugc/api.cpp b/ugc/api.cpp
index 7fb2a40954..e11d07380b 100644
--- a/ugc/api.cpp
+++ b/ugc/api.cpp
@@ -73,7 +73,7 @@ void Api::GetUGCToSendImpl(UGCJsonToSendCallback const & callback)
 {
   CHECK(callback, ());
   auto json = m_storage.GetUGCToSend();
-  callback(move(json));
+  callback(move(json), m_storage.GetNumberOfUnsynchronized());
 }
 
 void Api::SendingCompletedImpl()
diff --git a/ugc/api.hpp b/ugc/api.hpp
index 6b08de71b6..60dd7a7e12 100644
--- a/ugc/api.hpp
+++ b/ugc/api.hpp
@@ -20,7 +20,7 @@ class Api
 public:
   using UGCCallback = platform::SafeCallback<void(UGC const & ugc, UGCUpdate const & update)>;
   using UGCCallbackUnsafe = std::function<void(UGC const & ugc, UGCUpdate const & update)>;
-  using UGCJsonToSendCallback = std::function<void(std::string && jsonStr)>;
+  using UGCJsonToSendCallback = std::function<void(std::string && jsonStr, size_t numberOfUnsynchronized)>;
   using OnResultCallback = platform::SafeCallback<void(Storage::SettingResult const result)>;
 
   explicit Api(Index const & index);
diff --git a/ugc/storage.cpp b/ugc/storage.cpp
index 02f35eabd5..25289571c0 100644
--- a/ugc/storage.cpp
+++ b/ugc/storage.cpp
@@ -18,6 +18,7 @@
 #include <algorithm>
 #include <utility>
 
+#include "3party/Alohalytics/src/alohalytics.h"
 #include "3party/jansson/myjansson.hpp"
 
 namespace ugc
@@ -203,11 +204,20 @@ void Storage::Load()
     return;
   }
 
+  size_t numberOfUnsynchronized = 0;
   DeserializeUGCIndex(data, m_UGCIndexes);
   for (auto const & i : m_UGCIndexes)
   {
     if (i.m_deleted)
       ++m_numberOfDeleted;
+    else if (!i.m_synchronized)
+      ++numberOfUnsynchronized;
+  }
+
+  if (numberOfUnsynchronized > 1)
+  {
+    alohalytics::Stats::Instance().LogEvent("UGC_unsent",
+                                            {{"num", strings::to_string(numberOfUnsynchronized)}});
   }
 }
 
@@ -341,6 +351,17 @@ string Storage::GetUGCToSend() const
   return string(buffer.get());
 }
 
+size_t Storage::GetNumberOfUnsynchronized() const
+{
+  size_t numberOfUnsynchronized = 0;
+  for (auto const & i : m_UGCIndexes)
+  {
+    if (!i.m_deleted && !i.m_synchronized)
+      ++numberOfUnsynchronized;
+  }
+  return numberOfUnsynchronized;
+}
+
 void Storage::MarkAllAsSynchronized()
 {
   if (m_UGCIndexes.empty())
diff --git a/ugc/storage.hpp b/ugc/storage.hpp
index 8eb4022fa6..26b538d1f2 100644
--- a/ugc/storage.hpp
+++ b/ugc/storage.hpp
@@ -56,6 +56,7 @@ public:
   void MarkAllAsSynchronized();
   void Defragmentation();
   void Load();
+  size_t GetNumberOfUnsynchronized() const;
 
   /// Testing
   std::vector<UGCIndex> const & GetIndexesForTesting() const { return m_UGCIndexes; }