diff --git a/onnxruntime/test/providers/base_tester.cc b/onnxruntime/test/providers/base_tester.cc
index 459a8c71ad611..0f328ae84f8be 100644
--- a/onnxruntime/test/providers/base_tester.cc
+++ b/onnxruntime/test/providers/base_tester.cc
@@ -41,6 +41,14 @@ void DebugTrap() {
 #endif
 }  // namespace
 
+static inline bool use_cosine_similarity() {
+  static auto value = [&] {
+    const char* ptr = std::getenv("ORT_TEST_USE_COSINE_SIMILARITY");
+    return ptr != nullptr ? std::atoi(ptr) : 0;
+  }();
+  return value;
+}
+
 BaseTester::~BaseTester() {
 #ifndef NDEBUG
   if (!testing_function_called_) {
@@ -288,7 +296,8 @@ void BaseTester::ExecuteModel(Model& model, SessionType& session,
                               const std::unordered_map<std::string, OrtValue>& feeds,
                               const std::vector<std::string>& output_names,
                               const std::string& provider_type,
-                              bool allow_released_onnx_opset_only) {
+                              bool allow_released_onnx_opset_only,
+                              bool use_cosine_similarity) {
   fetches_.clear();
 
   std::string s1;
@@ -377,10 +386,10 @@ void BaseTester::ExecuteModel(Model& model, SessionType& session,
             }
 
             CheckOrtValuesAreEqual(name, expected_data.data, ort_value, expected_data.validation_params,
-                                   provider_type);
+                                   provider_type, use_cosine_similarity);
           } else {
             CheckOrtValuesAreEqual(name, expected_data.data, ort_value, expected_data.validation_params,
-                                   provider_type);
+                                   provider_type, false);
           }
 
           ++idx;
@@ -540,6 +549,7 @@ void BaseTester::Run(SessionOptions so,
   RunWithConfig(number_of_pre_packed_weights_counter, number_of_shared_pre_packed_weights_counter);
 }
 
+
 void BaseTester::RunWithConfig(size_t* number_of_pre_packed_weights_counter,
                                size_t* number_of_shared_pre_packed_weights_counter) {
   std::string cur_provider = "not set";
@@ -594,7 +604,8 @@ void BaseTester::RunWithConfig(size_t* number_of_pre_packed_weights_counter,
                          /*assign_ep_for_nodes=*/false,
                          allow_released_onnx_opset_only,
                          number_of_pre_packed_weights_counter,
-                         number_of_shared_pre_packed_weights_counter);
+                         number_of_shared_pre_packed_weights_counter,
+                         use_cosine_similarity());
     } else {
 #ifdef USE_TENSORRT
       // only run trt ep to reduce test time
@@ -677,7 +688,8 @@ void BaseTester::RunWithConfig(size_t* number_of_pre_packed_weights_counter,
             /*try_assign_ep_for_nodes=*/true,
             allow_released_onnx_opset_only,
             number_of_pre_packed_weights_counter,
-            number_of_shared_pre_packed_weights_counter);
+            number_of_shared_pre_packed_weights_counter,
+            use_cosine_similarity());
 
         // Run Models with subscribed run_options->config_options
         if (ctx_.run_options != nullptr &&
@@ -696,7 +708,8 @@ void BaseTester::RunWithConfig(size_t* number_of_pre_packed_weights_counter,
                 /*assign_ep_for_nodes=*/true,
                 allow_released_onnx_opset_only,
                 number_of_pre_packed_weights_counter,
-                number_of_shared_pre_packed_weights_counter);
+                number_of_shared_pre_packed_weights_counter,
+                use_cosine_similarity());
           }
         }
 
@@ -735,7 +748,8 @@ void BaseTester::ExecuteModelForEps(
     bool try_assign_ep_for_nodes,
     bool allow_released_onnx_opset_only,
     size_t* number_of_pre_packed_weights_counter,
-    size_t* number_of_shared_pre_packed_weights_counter) {
+    size_t* number_of_shared_pre_packed_weights_counter,
+    bool use_cosine_similarity) {
   for (auto& entry : execution_providers) {
     // Be noted, entry in execution providers passed in OpTester will be std::moved in the first BaseTester::Run(),
     // To make the error more obvious to debug (instead of a segment fault), we do check explicitly here.
@@ -785,7 +799,7 @@ void BaseTester::ExecuteModelForEps(
 
   ExecuteModel<InferenceSession>(
       model, session_object, expect_result, expected_failure_string,
-      run_options, feeds, output_names, provider_type, allow_released_onnx_opset_only);
+      run_options, feeds, output_names, provider_type, allow_released_onnx_opset_only, use_cosine_similarity);
 
   // After the model has initialized (happens in ExecuteModel),
   // we should be able to tell how many constant initializers were pre-packed
@@ -872,7 +886,8 @@ template void BaseTester::ExecuteModel<training::TrainingSession>(
     const RunOptions* run_options,
     const std::unordered_map<std::string, OrtValue>& feeds,
     const std::vector<std::string>& output_names, const std::string& provider_type,
-    bool allow_released_onnx_opset_only);
+    bool allow_released_onnx_opset_only,
+    bool use_cosine_similarity);
 #endif
 
 }  // namespace test
diff --git a/onnxruntime/test/providers/base_tester.h b/onnxruntime/test/providers/base_tester.h
index 5607e58315a12..63623cdbab500 100644
--- a/onnxruntime/test/providers/base_tester.h
+++ b/onnxruntime/test/providers/base_tester.h
@@ -658,7 +658,8 @@ class BaseTester {
                     const std::unordered_map<std::string, OrtValue>& feeds,
                     const std::vector<std::string>& output_names,
                     const std::string& provider_type,
-                    bool allow_released_onnx_opset_only = true);
+                    bool allow_released_onnx_opset_only = true,
+                    bool use_cosine_similarity = false);
 
   template <typename T>
   void AddData(std::vector<Data>& data, const char* name, const DimsVariant& dims_var, const T* values,
@@ -909,7 +910,8 @@ class BaseTester {
                           bool try_assign_ep_for_nodes,
                           bool allow_released_onnx_opset_only,
                           size_t* number_of_pre_packed_weights_counter,
-                          size_t* number_of_shared_pre_packed_weights_counter);
+                          size_t* number_of_shared_pre_packed_weights_counter,
+                          bool use_cosine_similarity);
 
   const std::string test_name_;
   const std::string domain_;
diff --git a/onnxruntime/test/providers/checkers.cc b/onnxruntime/test/providers/checkers.cc
index 85ccb8f175f62..a16250a5fa91b 100644
--- a/onnxruntime/test/providers/checkers.cc
+++ b/onnxruntime/test/providers/checkers.cc
@@ -47,7 +47,7 @@ void sort_expected_and_actual_buffers(std::vector<T>& expected,
 template <typename T>
 struct TensorCheck {
   void operator()(const Tensor& expected, const Tensor& actual, const ValidateOutputParams& params,
-                  const std::string& /*provider_type*/) const {
+                  const std::string& /*provider_type*/, bool use_cosine_similarity) const {
     Tensor expected_sorted, actual_sorted;
     const T* cur_expected;
     const T* cur_actual;
@@ -78,7 +78,8 @@ struct TensorCheck<uint8_t> {
   void operator()(const Tensor& expected,
                   const Tensor& actual,
                   const ValidateOutputParams& params,
-                  const std::string& provider_type) const {
+                  const std::string& provider_type,
+                  bool  use_cosine_similarity) const {
     const bool has_abs_err = params.absolute_error.has_value();
     const bool has_rel_err = params.relative_error.has_value();
 
@@ -133,7 +134,8 @@ struct TensorCheck<int8_t> {
   void operator()(const Tensor& expected,
                   const Tensor& actual,
                   const ValidateOutputParams& params,
-                  const std::string& /*provider_type*/) const {
+                  const std::string& /*provider_type*/,
+                  bool  use_cosine_similarity) const {
     Tensor expected_sorted, actual_sorted;
     const int8_t* cur_expected;
     const int8_t* cur_actual;
@@ -173,7 +175,8 @@ struct TensorCheck<double> {
   void operator()(const Tensor& expected,
                   const Tensor& actual,
                   const ValidateOutputParams& params,
-                  const std::string& /*provider_type*/) const {
+                  const std::string& /*provider_type*/,
+                  bool  use_cosine_similarity) const {
     auto size = actual.Shape().Size();
 
     bool has_abs_err = params.absolute_error.has_value();
@@ -227,7 +230,8 @@ template <typename TypeToCheck>
 void InternalNumericalCheck(const Tensor& expected,
                             const Tensor& actual,
                             const ValidateOutputParams& params,
-                            const std::string& /*provider_type*/) {
+                            const std::string& /*provider_type*/,
+			    bool  use_cosine_similarity) {
   const bool has_abs_err = params.absolute_error.has_value();
   const bool has_rel_err = params.relative_error.has_value();
 
@@ -251,7 +255,12 @@ void InternalNumericalCheck(const Tensor& expected,
 #else
   constexpr float threshold = 0.0001f;
 #endif
+  constexpr float cosine_similarity_threshold = 0.01f;
 
+  TypeToCheck dot = 0.0;
+  TypeToCheck denom_a = 0.0;
+  TypeToCheck denom_b = 0.0;
+  size_t diff_cnt = 0;
   for (int i = 0; i < size; ++i) {
     // NOTE: Check isnan first to work around MSVC linker bug when /LTCG:incremental is specified.
     // If the isinf check is first the isnan check and branch gets omitted
@@ -259,6 +268,13 @@ void InternalNumericalCheck(const Tensor& expected,
       EXPECT_TRUE(std::isnan(cur_actual[i])) << "Expected NaN. i:" << i;
     } else if (std::isinf(cur_expected[i])) {  // Test infinity for equality
       EXPECT_EQ(cur_expected[i], cur_actual[i]) << "Expected infinity. i:" << i;
+    } else if (use_cosine_similarity) {
+      if (abs(cur_expected[i] - cur_actual[i]) > threshold) {
+        dot += cur_expected[i] * cur_actual[i] ;
+        denom_a += cur_expected[i] * cur_expected[i] ;
+        denom_b += cur_actual[i] * cur_actual[i] ;
+        diff_cnt++;
+      }
     } else {
       if (!has_abs_err && !has_rel_err) {
         // the default for existing tests
@@ -275,6 +291,11 @@ void InternalNumericalCheck(const Tensor& expected,
       }
     }
   }
+
+  if (diff_cnt) {
+    float cos_sim = dot / (sqrt(denom_a) * sqrt(denom_b));
+    ASSERT_NEAR(cos_sim, 1.0f, cosine_similarity_threshold)<< "cos_sim is not 1.0 " << cos_sim ;
+  }
 }
 
 template <>
@@ -282,8 +303,9 @@ struct TensorCheck<float> {
   void operator()(const Tensor& expected,
                   const Tensor& actual,
                   const ValidateOutputParams& params,
-                  const std::string& provider_type) const {
-    InternalNumericalCheck<float>(expected, actual, params, provider_type);
+                  const std::string& provider_type,
+                  bool  use_cosine_similarity) const {
+    InternalNumericalCheck<float>(expected, actual, params, provider_type, use_cosine_similarity);
   }
 };
 
@@ -292,7 +314,8 @@ struct TensorCheck<MLFloat16> {
   void operator()(const Tensor& expected,
                   const Tensor& actual,
                   const ValidateOutputParams& params,
-                  const std::string& /*provider_type*/) const {
+                  const std::string& /*provider_type*/,
+                  bool  use_cosine_similarity) const {
     auto* cur_expected = expected.Data<MLFloat16>();
     auto* cur_actual = actual.Data<MLFloat16>();
     auto size = actual.Shape().Size();
@@ -346,7 +369,8 @@ struct TensorCheck<BFloat16> {
   void operator()(const Tensor& expected,
                   const Tensor& actual,
                   const ValidateOutputParams& params,
-                  const std::string& /*provider_type*/) const {
+                  const std::string& /*provider_type*/,
+                  bool  use_cosine_similarity) const {
     auto* cur_expected = expected.Data<BFloat16>();
     auto* cur_actual = actual.Data<BFloat16>();
     auto size = actual.Shape().Size();
@@ -397,14 +421,14 @@ struct TensorCheck<BFloat16> {
 // default Check
 template <typename T>
 void Check(std::string_view name, const OrtValue& expected, const T& actual,
-           const ValidateOutputParams& /*params*/, const std::string& /*provider_type*/) {
+           const ValidateOutputParams& /*params*/, const std::string& /*provider_type*/, bool use_cosine_similarity) {
   EXPECT_EQ(expected.Get<T>(), actual) << "name: " << name;
 }
 
 // Check for Tensors
 template <>
 void Check<Tensor>(std::string_view name, const OrtValue& expected, const Tensor& actual,
-                   const ValidateOutputParams& params, const std::string& provider_type) {
+                   const ValidateOutputParams& params, const std::string& provider_type, bool use_cosine_similarity) {
   const Tensor& expected_tensor = expected.Get<Tensor>();
   ORT_ENFORCE(expected_tensor.Shape() == actual.Shape(),
               "Expected output shape [", expected_tensor.Shape(),
@@ -420,13 +444,13 @@ void Check<Tensor>(std::string_view name, const OrtValue& expected, const Tensor
                               MLFloat16, BFloat16>
       t_disp(actual.GetElementType());
 
-  t_disp.Invoke<TensorCheck>(expected_tensor, actual, params, provider_type);
+  t_disp.Invoke<TensorCheck>(expected_tensor, actual, params, provider_type, use_cosine_similarity);
 }
 
 // Check for sequence of tensors
 template <>
 void Check<TensorSeq>(std::string_view name, const OrtValue& expected, const TensorSeq& actual,
-                      const ValidateOutputParams& params, const std::string& provider_type) {
+                      const ValidateOutputParams& params, const std::string& provider_type, bool use_cosine_similarity) {
   const auto& exp_seq = expected.Get<TensorSeq>();
 
   // first ensure data types match
@@ -454,15 +478,15 @@ void Check<TensorSeq>(std::string_view name, const OrtValue& expected, const Ten
       t_disp(element_type);
 
   for (size_t i = 0; i < actual_num_tensors; ++i) {
-    t_disp.Invoke<TensorCheck>(exp_seq.Get(i), actual.Get(i), params, provider_type);
+    t_disp.Invoke<TensorCheck>(exp_seq.Get(i), actual.Get(i), params, provider_type, use_cosine_similarity);
   }
 }
 
 template <typename Type>
 void CheckDispatch(MLDataType type, std::string_view name, const OrtValue& expected, const OrtValue& actual,
-                   const ValidateOutputParams& params, const std::string& provider_type) {
+                   const ValidateOutputParams& params, const std::string& provider_type, bool use_cosine_similarity) {
   if (type == DataTypeImpl::GetType<Type>()) {
-    Check<Type>(name, expected, actual.Get<Type>(), params, provider_type);
+    Check<Type>(name, expected, actual.Get<Type>(), params, provider_type, use_cosine_similarity);
   } else {
     ORT_THROW("OpTester:Check() not implemented for output tensor type of ", type);
   }
@@ -470,16 +494,16 @@ void CheckDispatch(MLDataType type, std::string_view name, const OrtValue& expec
 
 template <typename Type, typename Next, typename... Types>
 void CheckDispatch(MLDataType type, std::string_view name, const OrtValue& expected, const OrtValue& actual,
-                   const ValidateOutputParams& params, const std::string& provider_type) {
+                   const ValidateOutputParams& params, const std::string& provider_type, bool use_cosine_similarity) {
   if (type == DataTypeImpl::GetType<Type>()) {
-    Check<Type>(name, expected, actual.Get<Type>(), params, provider_type);
+    Check<Type>(name, expected, actual.Get<Type>(), params, provider_type, use_cosine_similarity);
   } else {
-    CheckDispatch<Next, Types...>(type, name, expected, actual, params, provider_type);
+    CheckDispatch<Next, Types...>(type, name, expected, actual, params, provider_type, use_cosine_similarity);
   }
 }
 
 void CheckOrtValuesAreEqual(std::string_view name, const OrtValue& expected, const OrtValue& actual,
-                            const ValidateOutputParams& params, const std::string& provider_type) {
+                            const ValidateOutputParams& params, const std::string& provider_type, bool use_cosine_similarity) {
   // Include provider_type in any error output
   SCOPED_TRACE(MakeString("provider type: ", provider_type));
 
@@ -488,7 +512,7 @@ void CheckOrtValuesAreEqual(std::string_view name, const OrtValue& expected, con
 #if !defined(DISABLE_ML_OPS)
       VectorMapStringToFloat, VectorMapInt64ToFloat,
 #endif
-      TensorSeq>(expected.Type(), name, expected, actual, params, provider_type);
+      TensorSeq>(expected.Type(), name, expected, actual, params, provider_type, use_cosine_similarity);
 }
 
 }  // namespace test
diff --git a/onnxruntime/test/providers/checkers.h b/onnxruntime/test/providers/checkers.h
index 54f3bb8f0fe5d..a10b05c19902a 100644
--- a/onnxruntime/test/providers/checkers.h
+++ b/onnxruntime/test/providers/checkers.h
@@ -27,7 +27,8 @@ struct ValidateOutputParams {
 /// <param name="params">Optional parameters to adjust how the check is performed.</param>
 /// <param name="provider_type">Execution provider type if relevant.</param>
 void CheckOrtValuesAreEqual(std::string_view name, const OrtValue& expected, const OrtValue& actual,
-                            const ValidateOutputParams& params = {}, const std::string& provider_type = "");
+                            const ValidateOutputParams& params = {}, const std::string& provider_type = "",
+                            bool use_cosine_similarity=false);
 
 }  // namespace test
 }  // namespace onnxruntime
diff --git a/onnxruntime/test/util/compare_ortvalue.cc b/onnxruntime/test/util/compare_ortvalue.cc
index 3d53d4a3a0193..118645ddc0b35 100644
--- a/onnxruntime/test/util/compare_ortvalue.cc
+++ b/onnxruntime/test/util/compare_ortvalue.cc
@@ -65,6 +65,26 @@ const char* ElementTypeToString(MLDataType type) {
   return DataTypeImpl::ToString(type);
 }
 
+static inline bool use_cosine_similarity() {
+  static auto value = [&] {
+    const char* ptr = std::getenv("ORT_TEST_USE_COSINE_SIMILARITY");
+    return ptr != nullptr ? std::atoi(ptr) : 0;
+  }();
+  return value;
+}
+
+template <typename TypeToCheck>
+TypeToCheck cosine_similarity(const TypeToCheck *A, const TypeToCheck *B, size_t Vector_Length)
+{
+    TypeToCheck dot = 0.0, denom_a = 0.0, denom_b = 0.0 ;
+     for(size_t i = 0u; i < Vector_Length; ++i) {
+        dot += A[i] * B[i] ;
+        denom_a += A[i] * A[i] ;
+        denom_b += B[i] * B[i] ;
+    }
+    return dot / (sqrt(denom_a) * sqrt(denom_b)) ;
+}
+
 /**
  * @brief Check if two values are closely matched with given tolerance.
 
@@ -105,12 +125,24 @@ std::pair<COMPARE_RESULT, std::string> CompareFloatResult(const Tensor& outvalue
   std::pair<COMPARE_RESULT, std::string> res = std::make_pair(COMPARE_RESULT::SUCCESS, "");
   double max_diff = 0;
   size_t diff_count = 0;
+  const float cosine_similarity_threshold = 0.99;
   for (size_t di = 0; di != size1; ++di) {
     const double real_value =
         post_processing ? std::max<double>(0.0, std::min<double>(255.0, real_output[di])) : real_output[di];
     const double diff = std::fabs(expected_output[di] - real_value);
     const double tol = per_sample_tolerance + relative_per_sample_tolerance * std::fabs(expected_output[di]);
     if (!IsResultCloselyMatch<double>(real_value, expected_output[di], diff, tol)) {
+      if (use_cosine_similarity()) {
+        float cos_sim = cosine_similarity(real_output, expected_output, size1);
+        if (abs(cos_sim) < cosine_similarity_threshold) {
+          res.first = COMPARE_RESULT::RESULT_DIFFERS;
+          std::ostringstream oss;
+          oss << std::hex << "results differed, cosine similarity factor is " << cos_sim << ".";
+          res.second = oss.str();
+        }
+        return res;
+      }
+
       res.first = COMPARE_RESULT::RESULT_DIFFERS;
       // update error message if this is a larger diff
       if (diff > max_diff || (std::isnan(diff) && !std::isnan(max_diff))) {