diff --git a/search/CMakeLists.txt b/search/CMakeLists.txt
index 4a258e8e2c..5c3cac49a5 100644
--- a/search/CMakeLists.txt
+++ b/search/CMakeLists.txt
@@ -24,6 +24,8 @@ set(
   engine.cpp
   engine.hpp
   everywhere_search_params.hpp
+  feature_loader.cpp
+  feature_loader.hpp
   feature_offset_match.hpp
   features_filter.cpp
   features_filter.hpp
diff --git a/search/feature_loader.cpp b/search/feature_loader.cpp
new file mode 100644
index 0000000000..32f939701e
--- /dev/null
+++ b/search/feature_loader.cpp
@@ -0,0 +1,26 @@
+#include "search/feature_loader.hpp"
+
+#include "indexer/feature_decl.hpp"
+
+#include "base/stl_add.hpp"
+
+namespace search
+{
+FeatureLoader::FeatureLoader(Index const & index) : m_index(index) {}
+
+bool FeatureLoader::Load(FeatureID const & id, FeatureType & ft)
+{
+  ASSERT(m_checker.CalledOnOriginalThread(), ());
+
+  auto const & mwmId = id.m_mwmId;
+  if (!m_guard || m_guard->GetId() != mwmId)
+    m_guard = my::make_unique<Index::FeaturesLoaderGuard>(m_index, mwmId);
+  return m_guard->GetFeatureByIndex(id.m_index, ft);
+}
+
+void FeatureLoader::Reset()
+{
+  ASSERT(m_checker.CalledOnOriginalThread(), ());
+  m_guard.reset();
+}
+}  // namespace search
diff --git a/search/feature_loader.hpp b/search/feature_loader.hpp
new file mode 100644
index 0000000000..132c4c00df
--- /dev/null
+++ b/search/feature_loader.hpp
@@ -0,0 +1,40 @@
+#pragma once
+
+#include "indexer/index.hpp"
+#include "indexer/scales.hpp"
+
+#include "base/assert.hpp"
+#include "base/macros.hpp"
+#include "base/thread_checker.hpp"
+
+#include <memory>
+#include <utility>
+
+class FeatureType;
+struct FeatureID;
+
+namespace search
+{
+class FeatureLoader
+{
+public:
+  explicit FeatureLoader(Index const & index);
+
+  WARN_UNUSED_RESULT bool Load(FeatureID const & id, FeatureType & ft);
+
+  void Reset();
+
+  template <typename ToDo>
+  void ForEachInRect(m2::RectD const & rect, ToDo && toDo)
+  {
+    ASSERT(m_checker.CalledOnOriginalThread(), ());
+    m_index.ForEachInRect(std::forward<ToDo>(toDo), rect, scales::GetUpperScale());
+  }
+
+private:
+  Index const & m_index;
+  std::unique_ptr<Index::FeaturesLoaderGuard> m_guard;
+
+  ThreadChecker m_checker;
+};
+}  // namespace search
diff --git a/search/house_detector.cpp b/search/house_detector.cpp
index ddf83f9eee..768ee8077a 100644
--- a/search/house_detector.cpp
+++ b/search/house_detector.cpp
@@ -223,26 +223,6 @@ bool House::GetNearbyMatch(ParsedNumber const & number) const
   return m_number.IsIntersect(number, HN_NEARBY_DISTANCE);
 }
 
-FeatureLoader::FeatureLoader(Index const & index) : m_index(index) {}
-
-void FeatureLoader::CreateLoader(MwmSet::MwmId const & mwmId)
-{
-  if (!m_guard || mwmId != m_guard->GetId())
-    m_guard = make_unique<Index::FeaturesLoaderGuard>(m_index, mwmId);
-}
-
-bool FeatureLoader::Load(FeatureID const & id, FeatureType & f)
-{
-  CreateLoader(id.m_mwmId);
-  return m_guard->GetFeatureByIndex(id.m_index, f);
-}
-
-template <class ToDo>
-void FeatureLoader::ForEachInRect(m2::RectD const & rect, ToDo toDo)
-{
-  m_index.ForEachInRect(toDo, rect, scales::GetUpperScale());
-}
-
 m2::RectD Street::GetLimitRect(double offsetMeters) const
 {
   m2::RectD rect;
@@ -481,7 +461,7 @@ int HouseDetector::LoadStreets(vector<FeatureID> const & ids)
     }
   }
 
-  m_loader.Free();
+  m_loader.Reset();
   return count;
 }
 
diff --git a/search/house_detector.hpp b/search/house_detector.hpp
index d23a4b8264..5c4ece56d1 100644
--- a/search/house_detector.hpp
+++ b/search/house_detector.hpp
@@ -1,4 +1,6 @@
 #pragma once
+
+#include "search/feature_loader.hpp"
 #include "search/projection_on_street.hpp"
 
 #include "indexer/feature_decl.hpp"
@@ -12,26 +14,10 @@
 #include "std/string.hpp"
 #include "std/queue.hpp"
 
+class Index;
 
 namespace search
 {
-
-class FeatureLoader
-{
-  Index const & m_index;
-  unique_ptr<Index::FeaturesLoaderGuard> m_guard;
-
-  void CreateLoader(MwmSet::MwmId const & mwmId);
-
-public:
-  FeatureLoader(Index const & index);
-
-  WARN_UNUSED_RESULT bool Load(FeatureID const & id, FeatureType & f);
-  inline void Free() { m_guard.reset(); }
-
-  template <class ToDo> void ForEachInRect(m2::RectD const & rect, ToDo toDo);
-};
-
 struct ParsedNumber
 {
   string m_fullN;
diff --git a/search/search.pro b/search/search.pro
index 2c11aa354f..f5a98532fe 100644
--- a/search/search.pro
+++ b/search/search.pro
@@ -23,6 +23,7 @@ HEADERS += \
     emitter.hpp \
     engine.hpp \
     everywhere_search_params.hpp \
+    feature_loader.hpp \
     feature_offset_match.hpp \
     features_filter.hpp \
     features_layer.hpp \
@@ -90,6 +91,7 @@ SOURCES += \
     dummy_rank_table.cpp \
     editor_delegate.cpp \
     engine.cpp \
+    feature_loader.cpp \
     features_filter.cpp \
     features_layer.cpp \
     features_layer_matcher.cpp \
diff --git a/search/search_quality/assessment_tool/CMakeLists.txt b/search/search_quality/assessment_tool/CMakeLists.txt
index dee27cb93c..31b3e3129d 100644
--- a/search/search_quality/assessment_tool/CMakeLists.txt
+++ b/search/search_quality/assessment_tool/CMakeLists.txt
@@ -19,7 +19,6 @@ set(
   languages_list.hpp
   main_model.cpp
   main_model.hpp
-  main_model.hpp
   main_view.cpp
   main_view.hpp
   model.hpp
diff --git a/search/search_quality/assessment_tool/context.cpp b/search/search_quality/assessment_tool/context.cpp
index 835cbbaf1f..d7cac1138d 100644
--- a/search/search_quality/assessment_tool/context.cpp
+++ b/search/search_quality/assessment_tool/context.cpp
@@ -1,5 +1,12 @@
 #include "search/search_quality/assessment_tool/context.hpp"
 
+#include "search/feature_loader.hpp"
+#include "search/search_quality/matcher.hpp"
+
+#include "base/assert.hpp"
+
+using namespace std;
+
 // Context -----------------------------------------------------------------------------------------
 void Context::Clear()
 {
@@ -8,6 +15,79 @@ void Context::Clear()
   m_initialized = false;
 }
 
+search::Sample Context::MakeSample(search::FeatureLoader & loader) const
+{
+  search::Sample sample = m_sample;
+
+  if (!m_initialized)
+    return sample;
+
+  auto const & relevances = m_edits.GetRelevances();
+
+  auto & results = sample.m_results;
+  results.clear();
+
+  CHECK_EQUAL(m_goldenMatching.size(), m_sample.m_results.size(), ());
+  CHECK_EQUAL(m_actualMatching.size(), relevances.size(), ());
+  CHECK_EQUAL(m_actualMatching.size(), m_results.GetCount(), ());
+
+  // Iterates over original (loaded from the file with search samples)
+  // results first.
+  for (size_t i = 0; i < m_sample.m_results.size(); ++i)
+  {
+    auto const j = m_goldenMatching[i];
+
+    // Some results weren't matched, so they weren't displayed to the
+    // assessor. But we want to keep them.
+    if (j == search::Matcher::kInvalidId)
+    {
+      results.push_back(m_sample.m_results[i]);
+      continue;
+    }
+
+    // No need to keep irrelevant results.
+    if (relevances[j] == search::Sample::Result::Relevance::Irrelevant)
+      continue;
+
+    auto result = m_sample.m_results[i];
+    result.m_relevance = relevances[j];
+    results.push_back(result);
+  }
+
+  // Iterates over results retrieved during assessment.
+  for (size_t i = 0; i < m_results.GetCount(); ++i)
+  {
+    auto const j = m_actualMatching[i];
+    if (j != search::Matcher::kInvalidId)
+    {
+      // This result was processed by the loop above.
+      continue;
+    }
+
+    // No need to keep irrelevant results.
+    if (relevances[i] == search::Sample::Result::Relevance::Irrelevant)
+      continue;
+
+    auto const & result = m_results.GetResult(i);
+    // No need in non-feature results.
+    if (result.GetResultType() != search::Result::RESULT_FEATURE)
+      continue;
+
+    FeatureType ft;
+    CHECK(loader.Load(result.GetFeatureID(), ft), ());
+    results.push_back(search::Sample::Result::Build(ft, relevances[i]));
+  }
+
+  return sample;
+}
+
+void Context::ApplyEdits()
+{
+  if (!m_initialized)
+    return;
+  m_edits.ResetRelevances(m_edits.GetRelevances());
+}
+
 // ContextList -------------------------------------------------------------------------------------
 ContextList::ContextList(OnUpdate onUpdate): m_onUpdate(onUpdate) {}
 
@@ -21,14 +101,28 @@ void ContextList::Resize(size_t size)
   m_hasChanges.resize(size);
   for (size_t i = oldSize; i < size; ++i)
   {
-    m_contexts.emplace_back([this, i]() {
+    m_contexts.emplace_back([this, i](Edits::Update const & update) {
       if (!m_hasChanges[i] && m_contexts[i].HasChanges())
         ++m_numChanges;
       if (m_hasChanges[i] && !m_contexts[i].HasChanges())
         --m_numChanges;
       m_hasChanges[i] = m_contexts[i].HasChanges();
       if (m_onUpdate)
-        m_onUpdate(i);
+        m_onUpdate(i, update);
     });
   }
 }
+
+vector<search::Sample> ContextList::MakeSamples(search::FeatureLoader & loader) const
+{
+  vector<search::Sample> samples;
+  for (auto const & context : m_contexts)
+    samples.push_back(context.MakeSample(loader));
+  return samples;
+}
+
+void ContextList::ApplyEdits()
+{
+  for (auto & context : m_contexts)
+    context.ApplyEdits();
+}
diff --git a/search/search_quality/assessment_tool/context.hpp b/search/search_quality/assessment_tool/context.hpp
index 3ea199cbe1..cfbcf744cf 100644
--- a/search/search_quality/assessment_tool/context.hpp
+++ b/search/search_quality/assessment_tool/context.hpp
@@ -11,6 +11,11 @@
 #include <string>
 #include <vector>
 
+namespace search
+{
+class FeatureLoader;
+}
+
 struct Context
 {
   explicit Context(Edits::OnUpdate onUpdate) : m_edits(onUpdate) {}
@@ -18,9 +23,19 @@ struct Context
   bool HasChanges() const { return m_initialized && m_edits.HasChanges(); }
   void Clear();
 
+  // Makes sample in accordance with uncommited edits.
+  search::Sample MakeSample(search::FeatureLoader & loader) const;
+
+  // Commits all edits.
+  void ApplyEdits();
+
   search::Sample m_sample;
   search::Results m_results;
   Edits m_edits;
+
+  std::vector<size_t> m_goldenMatching;
+  std::vector<size_t> m_actualMatching;
+
   bool m_initialized = false;
 };
 
@@ -48,7 +63,7 @@ public:
     ContextList const * m_contexts = nullptr;
   };
 
-  using OnUpdate = std::function<void(size_t index)>;
+  using OnUpdate = std::function<void(size_t index, Edits::Update const & update)>;
 
   explicit ContextList(OnUpdate onUpdate);
 
@@ -60,6 +75,12 @@ public:
 
   bool HasChanges() const { return m_numChanges != 0; }
 
+  // Generates search samples in accordance with uncommited edits.
+  std::vector<search::Sample> MakeSamples(search::FeatureLoader & loader) const;
+
+  // Commits all edits.
+  void ApplyEdits();
+
 private:
   std::vector<Context> m_contexts;
   std::vector<bool> m_hasChanges;
diff --git a/search/search_quality/assessment_tool/edits.cpp b/search/search_quality/assessment_tool/edits.cpp
index a8302ad9f1..522d858efc 100644
--- a/search/search_quality/assessment_tool/edits.cpp
+++ b/search/search_quality/assessment_tool/edits.cpp
@@ -20,10 +20,15 @@ Edits::Relevance Edits::RelevanceEditor::Get() const
   return relevances[m_index];
 }
 
+bool Edits::RelevanceEditor::HasChanges() const
+{
+  return m_parent.HasChanges(m_index);
+}
+
 // Edits -------------------------------------------------------------------------------------------
 void Edits::ResetRelevances(std::vector<Relevance> const & relevances)
 {
-  WithObserver([this, &relevances]() {
+  WithObserver(Update::AllRelevancesUpdate(), [this, &relevances]() {
     m_origRelevances = relevances;
     m_currRelevances = relevances;
     m_numEdits = 0;
@@ -32,7 +37,7 @@ void Edits::ResetRelevances(std::vector<Relevance> const & relevances)
 
 bool Edits::SetRelevance(size_t index, Relevance relevance)
 {
-  return WithObserver([this, index, relevance]() {
+  return WithObserver(Update::SingleRelevanceUpdate(index), [this, index, relevance]() {
     CHECK_LESS(index, m_currRelevances.size(), ());
     CHECK_EQUAL(m_currRelevances.size(), m_origRelevances.size(), ());
 
@@ -53,7 +58,7 @@ bool Edits::SetRelevance(size_t index, Relevance relevance)
 
 void Edits::Clear()
 {
-  WithObserver([this]() {
+  WithObserver(Update::AllRelevancesUpdate(), [this]() {
     m_origRelevances.clear();
     m_currRelevances.clear();
     m_numEdits = 0;
@@ -61,3 +66,9 @@ void Edits::Clear()
 }
 
 bool Edits::HasChanges() const { return m_numEdits != 0; }
+
+bool Edits::HasChanges(size_t index) const
+{
+  CHECK_LESS(index, m_currRelevances.size(), ());
+  return m_currRelevances[index] != m_origRelevances[index];
+}
diff --git a/search/search_quality/assessment_tool/edits.hpp b/search/search_quality/assessment_tool/edits.hpp
index d81df4d387..1c04b92dda 100644
--- a/search/search_quality/assessment_tool/edits.hpp
+++ b/search/search_quality/assessment_tool/edits.hpp
@@ -6,13 +6,38 @@
 
 #include <cstddef>
 #include <functional>
+#include <limits>
 #include <type_traits>
 #include <vector>
 
 class Edits
 {
 public:
-  using OnUpdate = std::function<void()>;
+  struct Update
+  {
+    static auto constexpr kInvalidIndex = std::numeric_limits<size_t>::max();
+
+    enum class Type
+    {
+      SingleRelevance,
+      AllRelevances
+    };
+
+    static Update AllRelevancesUpdate() { return Update{}; }
+
+    static Update SingleRelevanceUpdate(size_t index)
+    {
+      Update result;
+      result.m_index = index;
+      result.m_type = Type::SingleRelevance;
+      return result;
+    }
+
+    size_t m_index = kInvalidIndex;
+    Type m_type = Type::AllRelevances;
+  };
+
+  using OnUpdate = std::function<void(Update const & update)>;
   using Relevance = search::Sample::Result::Relevance;
 
   class RelevanceEditor
@@ -24,6 +49,7 @@ public:
     // differs from the original one.
     bool Set(Relevance relevance);
     Relevance Get() const;
+    bool HasChanges() const;
 
   private:
     Edits & m_parent;
@@ -38,18 +64,19 @@ public:
   // |relevance| differs from the original one.
   bool SetRelevance(size_t index, Relevance relevance);
 
-  std::vector<Relevance> const & GetRelevances() { return m_currRelevances; }
+  std::vector<Relevance> const & GetRelevances() const { return m_currRelevances; }
 
   void Clear();
   bool HasChanges() const;
+  bool HasChanges(size_t index) const;
 
 private:
   template <typename Fn>
-  typename std::result_of<Fn()>::type WithObserver(Fn && fn)
+  typename std::result_of<Fn()>::type WithObserver(Update const & update, Fn && fn)
   {
-    MY_SCOPE_GUARD(cleanup, [this]() {
+    MY_SCOPE_GUARD(cleanup, [&]() {
       if (m_onUpdate)
-        m_onUpdate();
+        m_onUpdate(update);
     });
     return fn();
   }
diff --git a/search/search_quality/assessment_tool/main_model.cpp b/search/search_quality/assessment_tool/main_model.cpp
index 3b46364959..64655241ff 100644
--- a/search/search_quality/assessment_tool/main_model.cpp
+++ b/search/search_quality/assessment_tool/main_model.cpp
@@ -1,5 +1,6 @@
 #include "search/search_quality/assessment_tool/main_model.hpp"
 
+#include "search/feature_loader.hpp"
 #include "search/search_quality/assessment_tool/view.hpp"
 #include "search/search_quality/matcher.hpp"
 
@@ -18,9 +19,11 @@
 
 #include <algorithm>
 #include <fstream>
+#include <functional>
 #include <iterator>
 
 using Relevance = search::Sample::Result::Relevance;
+using namespace std;
 
 // MainModel::SampleContext ------------------------------------------------------------------------
 
@@ -28,24 +31,27 @@ using Relevance = search::Sample::Result::Relevance;
 MainModel::MainModel(Framework & framework)
   : m_framework(framework)
   , m_index(m_framework.GetIndex())
-  , m_contexts([this](size_t index) { OnUpdate(index); })
+  , m_contexts([this](size_t index, Edits::Update const & update) { OnUpdate(index, update); })
 {
 }
 
-void MainModel::Open(std::string const & path)
+void MainModel::Open(string const & path)
 {
   CHECK(m_view, ());
 
-  std::ifstream ifs(path);
-  if (!ifs)
+  string contents;
+
   {
-    m_view->ShowError("Can't open file: " + path);
-    return;
+    ifstream ifs(path);
+    if (!ifs)
+    {
+      m_view->ShowError("Can't open file: " + path);
+      return;
+    }
+    contents.assign(istreambuf_iterator<char>(ifs), istreambuf_iterator<char>());
   }
 
-  std::string const contents((std::istreambuf_iterator<char>(ifs)),
-                             (std::istreambuf_iterator<char>()));
-  std::vector<search::Sample> samples;
+  vector<search::Sample> samples;
   if (!search::Sample::DeserializeFromJSON(contents, samples))
   {
     m_view->ShowError("Can't parse samples: " + path);
@@ -61,10 +67,41 @@ void MainModel::Open(std::string const & path)
     context.Clear();
     context.m_sample = samples[i];
   }
+  m_path = path;
 
   m_view->SetSamples(ContextList::SamplesSlice(m_contexts));
 }
 
+void MainModel::Save()
+{
+  CHECK(HasChanges(), ());
+  SaveAs(m_path);
+}
+
+void MainModel::SaveAs(string const & path)
+{
+  CHECK(HasChanges(), ());
+  CHECK(!path.empty(), ());
+
+  search::FeatureLoader loader(m_index);
+
+  string contents;
+  search::Sample::SerializeToJSON(m_contexts.MakeSamples(loader), contents);
+
+  {
+    ofstream ofs(path);
+    if (!ofs)
+    {
+      m_view->ShowError("Can't open file: " + path);
+      return;
+    }
+    copy(contents.begin(), contents.end(), ostreambuf_iterator<char>(ofs));
+  }
+
+  m_contexts.ApplyEdits();
+  m_path = path;
+}
+
 void MainModel::OnSampleSelected(int index)
 {
   CHECK(m_threadChecker.CalledOnOriginalThread(), ());
@@ -83,7 +120,8 @@ void MainModel::OnSampleSelected(int index)
 
   if (context.m_initialized)
   {
-    OnResults(timestamp, index, context.m_results, context.m_edits.GetRelevances());
+    OnResults(timestamp, index, context.m_results, context.m_edits.GetRelevances(),
+              context.m_goldenMatching, context.m_actualMatching);
     return;
   }
 
@@ -98,19 +136,17 @@ void MainModel::OnSampleSelected(int index)
     params.SetPosition(latLon.lat, latLon.lon);
 
     params.m_onResults = [this, index, sample, timestamp](search::Results const & results) {
-      std::vector<Relevance> relevances;
+      vector<Relevance> relevances;
+      vector<size_t> goldenMatching;
+      vector<size_t> actualMatching;
 
       if (results.IsEndedNormal())
       {
-        search::Matcher matcher(m_index);
-
-        std::vector<search::Result> const actual(results.begin(), results.end());
-        std::vector<size_t> goldenMatching;
-        {
-          std::vector<size_t> actualMatching;
-          matcher.Match(sample.m_results, actual, goldenMatching, actualMatching);
-        }
+        search::FeatureLoader loader(m_index);
+        search::Matcher matcher(loader);
 
+        vector<search::Result> const actual(results.begin(), results.end());
+        matcher.Match(sample.m_results, actual, goldenMatching, actualMatching);
         relevances.assign(actual.size(), Relevance::Irrelevant);
         for (size_t i = 0; i < goldenMatching.size(); ++i)
         {
@@ -119,25 +155,27 @@ void MainModel::OnSampleSelected(int index)
         }
       }
 
-      GetPlatform().RunOnGuiThread([this, timestamp, index, results, relevances]() {
-        OnResults(timestamp, index, results, relevances);
-      });
+      GetPlatform().RunOnGuiThread(bind(&MainModel::OnResults, this, timestamp, index, results,
+                                        relevances, goldenMatching, actualMatching));
     };
 
     m_queryHandle = engine.Search(params, sample.m_viewport);
   }
 }
 
-void MainModel::OnUpdate(size_t index)
+bool MainModel::HasChanges() { return m_contexts.HasChanges(); }
+
+void MainModel::OnUpdate(size_t index, Edits::Update const & update)
 {
   CHECK_LESS(index, m_contexts.Size(), ());
   auto & context = m_contexts[index];
-  m_view->OnSampleChanged(index, context.HasChanges());
+  m_view->OnSampleChanged(index, update, context.HasChanges());
   m_view->OnSamplesChanged(m_contexts.HasChanges());
 }
 
 void MainModel::OnResults(uint64_t timestamp, size_t index, search::Results const & results,
-                          std::vector<Relevance> const & relevances)
+                          vector<Relevance> const & relevances, vector<size_t> goldenMatching,
+                          vector<size_t> actualMatching)
 {
   CHECK(m_threadChecker.CalledOnOriginalThread(), ());
 
@@ -156,9 +194,11 @@ void MainModel::OnResults(uint64_t timestamp, size_t index, search::Results cons
   {
     context.m_results = results;
     context.m_edits.ResetRelevances(relevances);
+    context.m_goldenMatching = goldenMatching;
+    context.m_actualMatching = actualMatching;
     context.m_initialized = true;
   }
-  m_view->OnSampleChanged(index, context.HasChanges());
+  m_view->OnSampleChanged(index, Edits::Update::AllRelevancesUpdate(), context.HasChanges());
   m_view->EnableSampleEditing(index, context.m_edits);
 }
 
diff --git a/search/search_quality/assessment_tool/main_model.hpp b/search/search_quality/assessment_tool/main_model.hpp
index 27d7944395..39f05f4272 100644
--- a/search/search_quality/assessment_tool/main_model.hpp
+++ b/search/search_quality/assessment_tool/main_model.hpp
@@ -27,20 +27,29 @@ public:
 
   // Model overrides:
   void Open(std::string const & path) override;
+  void Save() override;
+  void SaveAs(std::string const & path) override;
+
   void OnSampleSelected(int index) override;
+  bool HasChanges() override;
 
 private:
-  void OnUpdate(size_t index);
+  void OnUpdate(size_t index, Edits::Update const & update);
 
   void OnResults(uint64_t timestamp, size_t index, search::Results const & results,
-                 std::vector<search::Sample::Result::Relevance> const & relevances);
+                 std::vector<search::Sample::Result::Relevance> const & relevances,
+                 std::vector<size_t> goldenMatching, std::vector<size_t> actualMatching);
 
   void ResetSearch();
 
   Framework & m_framework;
   Index const & m_index;
+
   ContextList m_contexts;
 
+  // Path to the last file search samples were loaded from or saved to.
+  std::string m_path;
+
   std::weak_ptr<search::ProcessorHandle> m_queryHandle;
   uint64_t m_queryTimestamp = 0;
   size_t m_numShownResults = 0;
diff --git a/search/search_quality/assessment_tool/main_view.cpp b/search/search_quality/assessment_tool/main_view.cpp
index 1470928199..7e2c75824d 100644
--- a/search/search_quality/assessment_tool/main_view.cpp
+++ b/search/search_quality/assessment_tool/main_view.cpp
@@ -25,6 +25,11 @@
 
 using Relevance = search::Sample::Result::Relevance;
 
+namespace
+{
+char const kJSON[] = "JSON files (*.json)";
+}  // namespace
+
 MainView::MainView(Framework & framework) : m_framework(framework)
 {
   QDesktopWidget const * desktop = QApplication::desktop();
@@ -48,6 +53,7 @@ MainView::~MainView()
 void MainView::SetSamples(ContextList::SamplesSlice const & samples)
 {
   m_samplesView->SetSamples(samples);
+  m_sampleView->Clear();
 }
 
 void MainView::ShowSample(size_t index, search::Sample const & sample, bool hasEdits)
@@ -57,7 +63,7 @@ void MainView::ShowSample(size_t index, search::Sample const & sample, bool hasE
   m_sampleView->SetContents(sample);
   m_sampleView->show();
 
-  OnSampleChanged(index, hasEdits);
+  OnSampleChanged(index, Edits::Update::AllRelevancesUpdate(), hasEdits);
 }
 
 void MainView::ShowResults(search::Results::Iter begin, search::Results::Iter end)
@@ -65,15 +71,16 @@ void MainView::ShowResults(search::Results::Iter begin, search::Results::Iter en
   m_sampleView->ShowResults(begin, end);
 }
 
-void MainView::OnSampleChanged(size_t index, bool hasEdits)
+void MainView::OnSampleChanged(size_t index, Edits::Update const & update, bool hasEdits)
 {
-  if (m_samplesView->IsSelected(index))
-  {
-    if (hasEdits)
-      m_sampleDock->setWindowTitle(tr("Sample *"));
-    else
-      m_sampleDock->setWindowTitle(tr("Sample"));
-  }
+  m_samplesView->OnUpdate(index);
+  if (!m_samplesView->IsSelected(index))
+    return;
+  if (hasEdits)
+    m_sampleDock->setWindowTitle(tr("Sample *"));
+  else
+    m_sampleDock->setWindowTitle(tr("Sample"));
+  m_sampleView->Update(update);
 }
 
 void MainView::OnSamplesChanged(bool hasEdits)
@@ -82,6 +89,8 @@ void MainView::OnSamplesChanged(bool hasEdits)
     m_samplesDock->setWindowTitle("Samples *");
   else
     m_samplesDock->setWindowTitle("Samples");
+  m_save->setEnabled(hasEdits);
+  m_saveAs->setEnabled(hasEdits);
 }
 
 void MainView::EnableSampleEditing(size_t index, Edits & edits)
@@ -113,13 +122,31 @@ void MainView::InitMenuBar()
   auto * fileMenu = bar->addMenu(tr("&File"));
 
   {
-    auto * open = new QAction(tr("&Open queries..."), this /* parent */);
+    auto * open = new QAction(tr("&Open samples..."), this /* parent */);
     open->setShortcuts(QKeySequence::Open);
-    open->setStatusTip(tr("Open the file with queries for assessment"));
+    open->setStatusTip(tr("Open the file with samples for assessment"));
     connect(open, &QAction::triggered, this, &MainView::Open);
     fileMenu->addAction(open);
   }
 
+  {
+    m_save = new QAction(tr("Save samples"), this /* parent */);
+    m_save->setShortcuts(QKeySequence::Save);
+    m_save->setStatusTip(tr("Save the file with assessed samples"));
+    m_save->setEnabled(false);
+    connect(m_save, &QAction::triggered, this, &MainView::Save);
+    fileMenu->addAction(m_save);
+  }
+
+  {
+    m_saveAs = new QAction(tr("Save samples as..."), this /* parent */);
+    m_saveAs->setShortcuts(QKeySequence::SaveAs);
+    m_saveAs->setStatusTip(tr("Save the file with assessed samples"));
+    m_saveAs->setEnabled(false);
+    connect(m_saveAs, &QAction::triggered, this, &MainView::SaveAs);
+    fileMenu->addAction(m_saveAs);
+  }
+
   fileMenu->addSeparator();
 
   {
@@ -185,8 +212,8 @@ void MainView::Open()
 {
   CHECK(m_model, ());
 
-  auto const file = QFileDialog::getOpenFileName(this, tr("Open samples..."), QString(),
-                                                 tr("JSON files (*.json)"))
+  auto const file = QFileDialog::getOpenFileName(this /* parent */, tr("Open samples..."),
+                                                 QString() /* dir */, tr(kJSON))
                         .toStdString();
   if (file.empty())
     return;
@@ -194,6 +221,17 @@ void MainView::Open()
   m_model->Open(file);
 }
 
+void MainView::Save() { m_model->Save(); }
+
+void MainView::SaveAs()
+{
+  auto const file = QFileDialog::getSaveFileName(this /* parent */, tr("Save samples as..."),
+                                                 QString() /* dir */, tr(kJSON))
+                        .toStdString();
+  if (!file.empty())
+    m_model->SaveAs(file);
+}
+
 QDockWidget * MainView::CreateDock(std::string const & title, QWidget & widget)
 {
   auto * dock = new QDockWidget(ToQString(title), this /* parent */, Qt::Widget);
diff --git a/search/search_quality/assessment_tool/main_view.hpp b/search/search_quality/assessment_tool/main_view.hpp
index a85d16a65d..f98c2baf7e 100644
--- a/search/search_quality/assessment_tool/main_view.hpp
+++ b/search/search_quality/assessment_tool/main_view.hpp
@@ -31,7 +31,7 @@ public:
   void ShowSample(size_t index, search::Sample const & sample, bool hasEdits) override;
   void ShowResults(search::Results::Iter begin, search::Results::Iter end) override;
 
-  void OnSampleChanged(size_t index, bool hasEdits) override;
+  void OnSampleChanged(size_t index, Edits::Update const & update, bool hasEdits) override;
   void EnableSampleEditing(size_t index, Edits & edits) override;
   void OnSamplesChanged(bool hasEdits) override;
 
@@ -46,6 +46,8 @@ private:
   void InitMenuBar();
 
   void Open();
+  void Save();
+  void SaveAs();
 
   QDockWidget * CreateDock(std::string const & title, QWidget & widget);
 
@@ -56,4 +58,7 @@ private:
 
   SampleView * m_sampleView = nullptr;
   QDockWidget * m_sampleDock = nullptr;
+
+  QAction * m_save = nullptr;
+  QAction * m_saveAs = nullptr;
 };
diff --git a/search/search_quality/assessment_tool/model.hpp b/search/search_quality/assessment_tool/model.hpp
index f36f09663e..4ee2c68efd 100644
--- a/search/search_quality/assessment_tool/model.hpp
+++ b/search/search_quality/assessment_tool/model.hpp
@@ -12,7 +12,11 @@ public:
   void SetView(View & view) { m_view = &view; }
 
   virtual void Open(std::string const & path) = 0;
+  virtual void Save() = 0;
+  virtual void SaveAs(std::string const & path) = 0;
+
   virtual void OnSampleSelected(int index) = 0;
+  virtual bool HasChanges() = 0;
 
 protected:
   View * m_view = nullptr;
diff --git a/search/search_quality/assessment_tool/result_view.cpp b/search/search_quality/assessment_tool/result_view.cpp
index faeb8e3da1..d672aa6743 100644
--- a/search/search_quality/assessment_tool/result_view.cpp
+++ b/search/search_quality/assessment_tool/result_view.cpp
@@ -61,6 +61,14 @@ void ResultView::EnableEditing(Edits::RelevanceEditor && editor)
   setEnabled(true);
 }
 
+void ResultView::Update()
+{
+  if (m_editor && m_editor->HasChanges())
+    setStyleSheet("#result {background: rgba(255, 255, 200, 50%)}");
+  else
+    setStyleSheet("");
+}
+
 void ResultView::Init()
 {
   auto * layout = new QVBoxLayout(this /* parent */);
@@ -124,9 +132,5 @@ void ResultView::OnRelevanceChanged()
   else if (m_vital->isChecked())
     relevance = Relevance::Vital;
 
-  bool changed = m_editor->Set(relevance);
-  if (changed)
-    setStyleSheet("#result {background: rgba(255, 255, 200, 50%)}");
-  else
-    setStyleSheet("");
+  m_editor->Set(relevance);
 }
diff --git a/search/search_quality/assessment_tool/result_view.hpp b/search/search_quality/assessment_tool/result_view.hpp
index 1201928b9b..4df28b80ed 100644
--- a/search/search_quality/assessment_tool/result_view.hpp
+++ b/search/search_quality/assessment_tool/result_view.hpp
@@ -24,6 +24,8 @@ public:
 
   void EnableEditing(Edits::RelevanceEditor && editor);
 
+  void Update();
+
 private:
   void Init();
   void SetContents(search::Result const & result);
diff --git a/search/search_quality/assessment_tool/results_view.cpp b/search/search_quality/assessment_tool/results_view.cpp
index 64c6edbc64..e535ca5d81 100644
--- a/search/search_quality/assessment_tool/results_view.cpp
+++ b/search/search_quality/assessment_tool/results_view.cpp
@@ -32,6 +32,20 @@ ResultView const & ResultsView::Get(size_t i) const
   return *m_results[i];
 }
 
+void ResultsView::Update(Edits::Update const & update)
+{
+  switch (update.m_type)
+  {
+  case Edits::Update::Type::SingleRelevance:
+    m_results[update.m_index]->Update();
+    break;
+  case Edits::Update::Type::AllRelevances:
+    for (auto * result : m_results)
+      result->Update();
+    break;
+  }
+}
+
 void ResultsView::Clear()
 {
   m_results.clear();
diff --git a/search/search_quality/assessment_tool/results_view.hpp b/search/search_quality/assessment_tool/results_view.hpp
index 633d1e11da..14ef24ebc0 100644
--- a/search/search_quality/assessment_tool/results_view.hpp
+++ b/search/search_quality/assessment_tool/results_view.hpp
@@ -1,5 +1,7 @@
 #pragma once
 
+#include "search/search_quality/assessment_tool/edits.hpp"
+
 #include <cstddef>
 #include <vector>
 
@@ -22,6 +24,7 @@ public:
 
   ResultView & Get(size_t i);
   ResultView const & Get(size_t i) const;
+  void Update(Edits::Update const & update);
 
   size_t Size() const { return m_results.size(); }
 
diff --git a/search/search_quality/assessment_tool/sample_view.cpp b/search/search_quality/assessment_tool/sample_view.cpp
index f390302c98..d48a87a338 100644
--- a/search/search_quality/assessment_tool/sample_view.cpp
+++ b/search/search_quality/assessment_tool/sample_view.cpp
@@ -59,6 +59,8 @@ SampleView::SampleView(QWidget * parent) : QWidget(parent)
   }
 
   setLayout(mainLayout);
+
+  Clear();
 }
 
 void SampleView::SetContents(search::Sample const & sample)
@@ -86,3 +88,13 @@ void SampleView::EnableEditing(Edits & edits)
   for (size_t i = 0; i < numRelevances; ++i)
     m_results->Get(i).EnableEditing(Edits::RelevanceEditor(*m_edits, i));
 }
+
+void SampleView::Update(Edits::Update const & update) { m_results->Update(update); }
+
+void SampleView::Clear()
+{
+  m_query->setText(QString());
+  m_langs->Select("default");
+  m_results->Clear();
+  m_edits = nullptr;
+}
diff --git a/search/search_quality/assessment_tool/sample_view.hpp b/search/search_quality/assessment_tool/sample_view.hpp
index 65cf06fea1..3f67bebb85 100644
--- a/search/search_quality/assessment_tool/sample_view.hpp
+++ b/search/search_quality/assessment_tool/sample_view.hpp
@@ -24,6 +24,9 @@ public:
 
   void EnableEditing(Edits & edits);
 
+  void Update(Edits::Update const & update);
+  void Clear();
+
 private:
   QLineEdit * m_query = nullptr;
   LanguagesList * m_langs = nullptr;
diff --git a/search/search_quality/assessment_tool/samples_view.cpp b/search/search_quality/assessment_tool/samples_view.cpp
index e6a8284f30..f35a9b8d3d 100644
--- a/search/search_quality/assessment_tool/samples_view.cpp
+++ b/search/search_quality/assessment_tool/samples_view.cpp
@@ -3,7 +3,6 @@
 #include "search/search_quality/assessment_tool/helpers.hpp"
 
 #include "base/assert.hpp"
-#include "base/checked_cast.hpp"
 
 #include <QtGui/QStandardItem>
 #include <QtWidgets/QHeaderView>
@@ -47,5 +46,5 @@ SamplesView::SamplesView(QWidget * parent) : QTableView(parent)
 
 bool SamplesView::IsSelected(size_t index) const
 {
-  return selectionModel()->isRowSelected(index, QModelIndex());
+  return selectionModel()->isRowSelected(base::checked_cast<int>(index), QModelIndex());
 }
diff --git a/search/search_quality/assessment_tool/samples_view.hpp b/search/search_quality/assessment_tool/samples_view.hpp
index 007b595eb1..502c2fb2db 100644
--- a/search/search_quality/assessment_tool/samples_view.hpp
+++ b/search/search_quality/assessment_tool/samples_view.hpp
@@ -2,6 +2,8 @@
 
 #include "search/search_quality/assessment_tool/context.hpp"
 
+#include "base/checked_cast.hpp"
+
 #include <cstddef>
 #include <vector>
 
@@ -15,6 +17,7 @@ public:
 
   void SetSamples(ContextList::SamplesSlice const & samples) { m_model->SetSamples(samples); }
   bool IsSelected(size_t index) const;
+  void OnUpdate(size_t index) { m_model->OnUpdate(index); }
 
 private:
   class Model : public QStandardItemModel
@@ -27,7 +30,15 @@ private:
       removeRows(0, rowCount());
       m_samples = samples;
       if (m_samples.IsValid())
-        insertRows(0, m_samples.Size());
+        insertRows(0, base::checked_cast<int>(m_samples.Size()));
+    }
+
+    void OnUpdate(size_t index)
+    {
+      auto const ix = createIndex(base::checked_cast<int>(index) /* row */, 0 /* column */);
+
+      // Need to refresh view when some item is updated.
+      emit dataChanged(ix, ix);
     }
 
     // QStandardItemModel overrides:
diff --git a/search/search_quality/assessment_tool/view.hpp b/search/search_quality/assessment_tool/view.hpp
index 736553f8f5..a8797c3a59 100644
--- a/search/search_quality/assessment_tool/view.hpp
+++ b/search/search_quality/assessment_tool/view.hpp
@@ -2,6 +2,7 @@
 
 #include "search/result.hpp"
 #include "search/search_quality/assessment_tool/context.hpp"
+#include "search/search_quality/assessment_tool/edits.hpp"
 
 #include <cstddef>
 #include <string>
@@ -21,7 +22,7 @@ public:
   virtual void ShowSample(size_t index, search::Sample const & sample, bool hasEdits) = 0;
   virtual void ShowResults(search::Results::Iter begin, search::Results::Iter end) = 0;
 
-  virtual void OnSampleChanged(size_t index, bool hasEdits) = 0;
+  virtual void OnSampleChanged(size_t index, Edits::Update const & update, bool hasEdits) = 0;
   virtual void EnableSampleEditing(size_t index, Edits & edits) = 0;
   virtual void OnSamplesChanged(bool hasEdits) = 0;
 
diff --git a/search/search_quality/features_collector_tool/features_collector_tool.cpp b/search/search_quality/features_collector_tool/features_collector_tool.cpp
index aeaf39063f..598f11c913 100644
--- a/search/search_quality/features_collector_tool/features_collector_tool.cpp
+++ b/search/search_quality/features_collector_tool/features_collector_tool.cpp
@@ -1,3 +1,4 @@
+#include "search/feature_loader.hpp"
 #include "search/ranking_info.hpp"
 #include "search/result.hpp"
 #include "search/search_quality/helpers.hpp"
@@ -162,7 +163,8 @@ int main(int argc, char * argv[])
   }
 
   vector<Stats> stats(samples.size());
-  Matcher matcher(engine);
+  FeatureLoader loader(engine);
+  Matcher matcher(loader);
 
   cout << "SampleId,";
   RankingInfo::PrintCSVHeader(cout);
diff --git a/search/search_quality/matcher.cpp b/search/search_quality/matcher.cpp
index d0c831f4c3..12988ae066 100644
--- a/search/search_quality/matcher.cpp
+++ b/search/search_quality/matcher.cpp
@@ -1,8 +1,9 @@
 #include "search/search_quality/matcher.hpp"
 
+#include "search/feature_loader.hpp"
+
 #include "indexer/feature.hpp"
 #include "indexer/feature_algo.hpp"
-#include "indexer/feature_decl.hpp"
 
 #include "base/string_utils.hpp"
 
@@ -15,7 +16,7 @@ namespace search
 // static
 size_t constexpr Matcher::kInvalidId;
 
-Matcher::Matcher(Index const & index) : m_index(index) {}
+Matcher::Matcher(FeatureLoader & loader) : m_loader(loader) {}
 
 void Matcher::Match(std::vector<Sample::Result> const & golden, std::vector<Result> const & actual,
                     std::vector<size_t> & goldenMatching, std::vector<size_t> & actualMatching)
@@ -49,14 +50,6 @@ void Matcher::Match(std::vector<Sample::Result> const & golden, std::vector<Resu
   }
 }
 
-bool Matcher::GetFeature(FeatureID const & id, FeatureType & ft)
-{
-  auto const & mwmId = id.m_mwmId;
-  if (!m_guard || m_guard->GetId() != mwmId)
-    m_guard = my::make_unique<Index::FeaturesLoaderGuard>(m_index, mwmId);
-  return m_guard->GetFeatureByIndex(id.m_index, ft);
-}
-
 bool Matcher::Matches(Sample::Result const & golden, search::Result const & actual)
 {
   static double constexpr kToleranceMeters = 50;
@@ -65,7 +58,7 @@ bool Matcher::Matches(Sample::Result const & golden, search::Result const & actu
     return false;
 
   FeatureType ft;
-  if (!GetFeature(actual.GetFeatureID(), ft))
+  if (!m_loader.Load(actual.GetFeatureID(), ft))
     return false;
 
   auto const houseNumber = ft.GetHouseNumber();
diff --git a/search/search_quality/matcher.hpp b/search/search_quality/matcher.hpp
index 90de3a4904..73362486c5 100644
--- a/search/search_quality/matcher.hpp
+++ b/search/search_quality/matcher.hpp
@@ -3,36 +3,27 @@
 #include "search/result.hpp"
 #include "search/search_quality/sample.hpp"
 
-#include "indexer/index.hpp"
-
-#include "base/macros.hpp"
-
 #include <cstdint>
 #include <limits>
-#include <memory>
 #include <vector>
 
-class FeatureType;
-struct FeatureID;
-
 namespace search
 {
+class FeatureLoader;
+
 class Matcher
 {
 public:
   static size_t constexpr kInvalidId = std::numeric_limits<size_t>::max();
 
-  Matcher(Index const & index);
+  explicit Matcher(FeatureLoader & loader);
 
   void Match(std::vector<Sample::Result> const & golden, std::vector<Result> const & actual,
              std::vector<size_t> & goldenMatching, std::vector<size_t> & actualMatching);
 
 private:
-  WARN_UNUSED_RESULT bool GetFeature(FeatureID const & id, FeatureType & ft);
-
   bool Matches(Sample::Result const & golden, Result const & actual);
 
-  Index const & m_index;
-  std::unique_ptr<Index::FeaturesLoaderGuard> m_guard;
+  FeatureLoader & m_loader;
 };
 }  // namespace search
diff --git a/search/search_quality/sample.cpp b/search/search_quality/sample.cpp
index c433933d21..15b1d78730 100644
--- a/search/search_quality/sample.cpp
+++ b/search/search_quality/sample.cpp
@@ -2,6 +2,10 @@
 
 #include "search/search_quality/helpers.hpp"
 
+#include "indexer/feature.hpp"
+#include "indexer/feature_algo.hpp"
+#include "indexer/feature_data.hpp"
+
 #include "base/logging.hpp"
 #include "base/string_utils.hpp"
 
@@ -51,6 +55,22 @@ struct FreeDeletor
 
 namespace search
 {
+// static
+Sample::Result Sample::Result::Build(FeatureType & ft, Relevance relevance)
+{
+  Sample::Result r;
+  r.m_pos = feature::GetCenter(ft);
+  {
+    string name;
+    ft.GetReadableName(name);
+    r.m_name = strings::MakeUniString(name);
+  }
+  r.m_houseNumber = ft.GetHouseNumber();
+  r.m_types = feature::TypesHolder(ft).ToObjectNames();
+  r.m_relevance = relevance;
+  return r;
+}
+
 bool Sample::Result::operator<(Sample::Result const & rhs) const
 {
   if (m_pos != rhs.m_pos)
diff --git a/search/search_quality/sample.hpp b/search/search_quality/sample.hpp
index 779d6376c0..e82f34f9f6 100644
--- a/search/search_quality/sample.hpp
+++ b/search/search_quality/sample.hpp
@@ -10,6 +10,8 @@
 #include <string>
 #include <vector>
 
+class FeatureType;
+
 namespace search
 {
 struct Sample
@@ -23,6 +25,8 @@ struct Sample
       Vital
     };
 
+    static Result Build(FeatureType & ft, Relevance relevance);
+
     bool operator<(Result const & rhs) const;
 
     bool operator==(Result const & rhs) const;