diff --git a/tensorflow/lite/experimental/tensorboard/BUILD b/tensorflow/lite/experimental/tensorboard/BUILD
new file mode 100644
index 00000000000..b156b5b1549
--- /dev/null
+++ b/tensorflow/lite/experimental/tensorboard/BUILD
@@ -0,0 +1,25 @@
+# TFLite modules to support TensorBoard plugin.
+package(default_visibility = ["//tensorflow:internal"])
+
+licenses(["notice"])  # Apache 2.0
+
+py_library(
+    name = "ops_util",
+    srcs = ["ops_util.py"],
+    srcs_version = "PY2AND3",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//tensorflow/lite/toco/python:tensorflow_wrap_toco",
+        "//tensorflow/python:util",
+    ],
+)
+
+py_test(
+    name = "ops_util_test",
+    srcs = ["ops_util_test.py"],
+    srcs_version = "PY2AND3",
+    deps = [
+        ":ops_util",
+        "//tensorflow/python:client_testlib",
+    ],
+)
diff --git a/tensorflow/lite/experimental/tensorboard/README.md b/tensorflow/lite/experimental/tensorboard/README.md
new file mode 100644
index 00000000000..fdbd160a2a5
--- /dev/null
+++ b/tensorflow/lite/experimental/tensorboard/README.md
@@ -0,0 +1,4 @@
+This folder contains basic modules to support TFLite plugin for TensorBoard.
+
+Warning: Everything in this directory is experimental and highly subject to
+changes.
diff --git a/tensorflow/lite/experimental/tensorboard/ops_util.py b/tensorflow/lite/experimental/tensorboard/ops_util.py
new file mode 100644
index 00000000000..8f48f77b301
--- /dev/null
+++ b/tensorflow/lite/experimental/tensorboard/ops_util.py
@@ -0,0 +1,49 @@
+# Copyright 2019 The TensorFlow Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+"""Ops util to handle ops for Lite."""
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import collections
+from tensorflow.lite.toco.python import tensorflow_wrap_toco
+from tensorflow.python.util.tf_export import tf_export
+
+
+class SupportedOp(collections.namedtuple("SupportedOp", ["op"])):
+  """Spec of supported ops.
+
+  Args:
+    op: string of op name.
+  """
+
+
+@tf_export("lite.experimental.get_potentially_supported_ops")
+def get_potentially_supported_ops():
+  """Returns operations potentially supported by TensorFlow Lite.
+
+  The potentially support list contains a list of ops that are partially or
+  fully supported, which is derived by simply scanning op names to check whether
+  they can be handled without real conversion and specific parameters.
+
+  Given that some ops may be partially supported, the optimal way to determine
+  if a model's operations are supported is by converting using the TensorFlow
+  Lite converter.
+
+  Returns:
+    A list of SupportedOp.
+  """
+  ops = tensorflow_wrap_toco.TocoGetPotentiallySupportedOps()
+  return [SupportedOp(o["op"]) for o in ops]
diff --git a/tensorflow/lite/experimental/tensorboard/ops_util_test.py b/tensorflow/lite/experimental/tensorboard/ops_util_test.py
new file mode 100644
index 00000000000..38966676dde
--- /dev/null
+++ b/tensorflow/lite/experimental/tensorboard/ops_util_test.py
@@ -0,0 +1,39 @@
+# Copyright 2018 The TensorFlow Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+"""Tests for backend."""
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+from tensorflow.lite.experimental.tensorboard import ops_util
+from tensorflow.python.platform import test
+
+
+class OpsUtilTest(test.TestCase):
+
+  def testGetPotentiallySupportedOps(self):
+    ops = ops_util.get_potentially_supported_ops()
+    # See GetTensorFlowNodeConverterMap() in
+    # tensorflow/lite/toco/import_tensorflow.cc
+    self.assertIsInstance(ops, list)
+    # Test partial ops that surely exist in the list.
+    self.assertIn(ops_util.SupportedOp("Add"), ops)
+    self.assertIn(ops_util.SupportedOp("Log"), ops)
+    self.assertIn(ops_util.SupportedOp("Sigmoid"), ops)
+    self.assertIn(ops_util.SupportedOp("Softmax"), ops)
+
+
+if __name__ == "__main__":
+  test.main()
diff --git a/tensorflow/lite/python/BUILD b/tensorflow/lite/python/BUILD
index fae6540028c..a1bfe4898bc 100644
--- a/tensorflow/lite/python/BUILD
+++ b/tensorflow/lite/python/BUILD
@@ -73,6 +73,7 @@ py_library(
         ":op_hint",
         ":util",
         "//tensorflow/lite/experimental/examples/lstm:tflite_lstm_ops",
+        "//tensorflow/lite/experimental/tensorboard:ops_util",
         "//tensorflow/lite/python/optimize:calibrator",
         "//tensorflow/python:graph_util",
         "//tensorflow/python/keras",
diff --git a/tensorflow/lite/python/lite.py b/tensorflow/lite/python/lite.py
index dd5a89bf90f..751f07bb209 100644
--- a/tensorflow/lite/python/lite.py
+++ b/tensorflow/lite/python/lite.py
@@ -24,9 +24,11 @@ from six import PY3
 
 from google.protobuf import text_format as _text_format
 from google.protobuf.message import DecodeError
+from tensorflow.core.framework import graph_pb2 as _graph_pb2
 from tensorflow.lite.experimental.examples.lstm.rnn import dynamic_rnn  # pylint: disable=unused-import
 from tensorflow.lite.experimental.examples.lstm.rnn_cell import TFLiteLSTMCell  # pylint: disable=unused-import
 from tensorflow.lite.experimental.examples.lstm.rnn_cell import TfLiteRNNCell  # pylint: disable=unused-import
+from tensorflow.lite.experimental.tensorboard.ops_util import get_potentially_supported_ops  # pylint: disable=unused-import
 from tensorflow.lite.python import lite_constants as constants
 from tensorflow.lite.python.convert import build_toco_convert_protos  # pylint: disable=unused-import
 from tensorflow.lite.python.convert import ConverterError  # pylint: disable=unused-import
@@ -47,7 +49,6 @@ from tensorflow.lite.python.util import get_tensors_from_tensor_names as _get_te
 from tensorflow.lite.python.util import is_frozen_graph as _is_frozen_graph
 from tensorflow.lite.python.util import run_graph_optimizations as _run_graph_optimizations
 from tensorflow.lite.python.util import set_tensor_shapes as _set_tensor_shapes
-from tensorflow.core.framework import graph_pb2 as _graph_pb2
 from tensorflow.python import keras as _keras
 from tensorflow.python.client import session as _session
 from tensorflow.python.eager import def_function as _def_function
diff --git a/tensorflow/lite/python/lite_test.py b/tensorflow/lite/python/lite_test.py
index a218497b63b..0ff6f5865ee 100644
--- a/tensorflow/lite/python/lite_test.py
+++ b/tensorflow/lite/python/lite_test.py
@@ -1394,5 +1394,11 @@ class FromKerasFile(test_util.TensorFlowTestCase):
     interpreter.allocate_tensors()
 
 
+class ImportOpsUtilTest(test_util.TensorFlowTestCase):
+
+  def testGetPotentiallySupportedOps(self):
+    self.assertIsNotNone(lite.get_potentially_supported_ops())
+
+
 if __name__ == '__main__':
   test.main()
diff --git a/tensorflow/lite/toco/import_tensorflow.cc b/tensorflow/lite/toco/import_tensorflow.cc
index 6b5e68c533f..852b2b7480e 100644
--- a/tensorflow/lite/toco/import_tensorflow.cc
+++ b/tensorflow/lite/toco/import_tensorflow.cc
@@ -2629,4 +2629,16 @@ std::unique_ptr<Model> ImportTensorFlowGraphDef(
   }
   return ImportTensorFlowGraphDef(model_flags, tf_import_flags, *tf_graph);
 }
+
+std::vector<std::string> GetPotentiallySupportedOps() {
+  std::vector<std::string> supported_ops;
+  const internal::ConverterMapType& converter_map =
+      internal::GetTensorFlowNodeConverterMap();
+
+  for (const auto& item : converter_map) {
+    supported_ops.push_back(item.first);
+  }
+  return supported_ops;
+}
+
 }  // namespace toco
diff --git a/tensorflow/lite/toco/import_tensorflow.h b/tensorflow/lite/toco/import_tensorflow.h
index 5b74ff2bc31..4ada25e2fbe 100644
--- a/tensorflow/lite/toco/import_tensorflow.h
+++ b/tensorflow/lite/toco/import_tensorflow.h
@@ -17,9 +17,9 @@ limitations under the License.
 
 #include <memory>
 #include <string>
+#include "tensorflow/core/framework/graph.pb.h"
 #include "tensorflow/lite/toco/model.h"
 #include "tensorflow/lite/toco/model_flags.pb.h"
-#include "tensorflow/core/framework/graph.pb.h"
 
 namespace toco {
 
@@ -34,14 +34,20 @@ struct TensorFlowImportFlags {
   bool import_all_ops_as_unsupported = false;
 };
 
+// Converts TOCO model from TensorFlow GraphDef with given flags.
 std::unique_ptr<Model> ImportTensorFlowGraphDef(
     const ModelFlags& model_flags, const TensorFlowImportFlags& tf_import_flags,
     const tensorflow::GraphDef& graph_def);
 
+// Converts TOCO model from the file content of TensorFlow GraphDef with given
+// flags.
 std::unique_ptr<Model> ImportTensorFlowGraphDef(
     const ModelFlags& model_flags, const TensorFlowImportFlags& tf_import_flags,
     const string& input_file_contents);
 
+// Gets a list of supported ops by their names.
+std::vector<std::string> GetPotentiallySupportedOps();
+
 }  // namespace toco
 
 #endif  // TENSORFLOW_LITE_TOCO_IMPORT_TENSORFLOW_H_
diff --git a/tensorflow/lite/toco/python/toco.i b/tensorflow/lite/toco/python/toco.i
index c7dfdc35ab2..de10fca99e8 100644
--- a/tensorflow/lite/toco/python/toco.i
+++ b/tensorflow/lite/toco/python/toco.i
@@ -32,4 +32,7 @@ PyObject* TocoConvert(PyObject* model_flags_proto_txt_raw,
                         PyObject* input_contents_txt_raw,
                         bool extended_return = false);
 
+// Returns a list of names of all ops potentially supported by tflite.
+PyObject* TocoGetPotentiallySupportedOps();
+
 } // namespace toco
\ No newline at end of file
diff --git a/tensorflow/lite/toco/python/toco_python_api.cc b/tensorflow/lite/toco/python/toco_python_api.cc
index 6fad092f35a..22557a34cc5 100644
--- a/tensorflow/lite/toco/python/toco_python_api.cc
+++ b/tensorflow/lite/toco/python/toco_python_api.cc
@@ -12,11 +12,13 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 ==============================================================================*/
+#include <map>
 #include <string>
 #include <vector>
-#include "tensorflow/core/platform/logging.h"
 
+#include "tensorflow/core/platform/logging.h"
 #include "tensorflow/lite/python/interpreter_wrapper/python_utils.h"
+#include "tensorflow/lite/toco/import_tensorflow.h"
 #include "tensorflow/lite/toco/model_flags.pb.h"
 #include "tensorflow/lite/toco/python/toco_python_api.h"
 #include "tensorflow/lite/toco/toco_flags.pb.h"
@@ -49,21 +51,32 @@ PyObject* TocoConvert(PyObject* model_flags_proto_txt_raw,
   bool error;
   std::string model_flags_proto_txt =
       ConvertArg(model_flags_proto_txt_raw, &error);
-  if (error) return nullptr;
+  if (error) {
+    PyErr_SetString(PyExc_ValueError, "Model flags are invalid.");
+    return nullptr;
+  }
   std::string toco_flags_proto_txt =
       ConvertArg(toco_flags_proto_txt_raw, &error);
-  if (error) return nullptr;
+  if (error) {
+    PyErr_SetString(PyExc_ValueError, "Toco flags are invalid.");
+    return nullptr;
+  }
   std::string input_contents_txt = ConvertArg(input_contents_txt_raw, &error);
-  if (error) return nullptr;
+  if (error) {
+    PyErr_SetString(PyExc_ValueError, "Input GraphDef is invalid.");
+    return nullptr;
+  }
 
   // Use TOCO to produce new outputs.
   toco::ModelFlags model_flags;
   if (!model_flags.ParseFromString(model_flags_proto_txt)) {
-    LOG(FATAL) << "Model proto failed to parse." << std::endl;
+    PyErr_SetString(PyExc_ValueError, "Model proto failed to parse.");
+    return nullptr;
   }
   toco::TocoFlags toco_flags;
   if (!toco_flags.ParseFromString(toco_flags_proto_txt)) {
-    LOG(FATAL) << "Toco proto failed to parse." << std::endl;
+    PyErr_SetString(PyExc_ValueError, "Toco proto failed to parse.");
+    return nullptr;
   }
 
   auto& dump_options = *GraphVizDumpOptions::singleton();
@@ -100,4 +113,16 @@ PyObject* TocoConvert(PyObject* model_flags_proto_txt_raw,
       output_file_contents_txt.data(), output_file_contents_txt.size());
 }
 
+PyObject* TocoGetPotentiallySupportedOps() {
+  std::vector<std::string> supported_ops = toco::GetPotentiallySupportedOps();
+  PyObject* list = PyList_New(supported_ops.size());
+  for (size_t i = 0; i < supported_ops.size(); ++i) {
+    const string& op = supported_ops[i];
+    PyObject* op_dict = PyDict_New();
+    PyDict_SetItemString(op_dict, "op", PyUnicode_FromString(op.c_str()));
+    PyList_SetItem(list, i, op_dict);
+  }
+  return list;
+}
+
 }  // namespace toco
diff --git a/tensorflow/lite/toco/python/toco_python_api.h b/tensorflow/lite/toco/python/toco_python_api.h
index 4ab0961e127..20390c32a5e 100644
--- a/tensorflow/lite/toco/python/toco_python_api.h
+++ b/tensorflow/lite/toco/python/toco_python_api.h
@@ -31,6 +31,9 @@ PyObject* TocoConvert(PyObject* model_flags_proto_txt_raw,
                       PyObject* input_contents_txt_raw,
                       bool extended_return = false);
 
+// Returns a list of names of all ops potentially supported by tflite.
+PyObject* TocoGetPotentiallySupportedOps();
+
 }  // namespace toco
 
 #endif  // TENSORFLOW_LITE_TOCO_PYTHON_TOCO_PYTHON_API_H_
diff --git a/tensorflow/python/tools/freeze_graph.py b/tensorflow/python/tools/freeze_graph.py
index ab82ee9fd41..f23cf827470 100644
--- a/tensorflow/python/tools/freeze_graph.py
+++ b/tensorflow/python/tools/freeze_graph.py
@@ -125,12 +125,12 @@ def freeze_graph_with_def_protos(input_graph_def,
   # 'input_checkpoint' may be a prefix if we're using Saver V2 format
   if (not input_saved_model_dir and
       not checkpoint_management.checkpoint_exists(input_checkpoint)):
-    print("Input checkpoint '" + input_checkpoint + "' doesn't exist!")
-    return -1
+    raise ValueError("Input checkpoint '" + input_checkpoint +
+                     "' doesn't exist!")
 
   if not output_node_names:
-    print("You need to supply the name of a node to --output_node_names.")
-    return -1
+    raise ValueError(
+        "You need to supply the name of a node to --output_node_names.")
 
   # Remove all the explicit device specifications for this node. This helps to
   # make the graph more portable.
@@ -193,14 +193,15 @@ def freeze_graph_with_def_protos(input_graph_def,
         # tensors. Partition variables are Identity tensors that cannot be
         # handled by Saver.
         if has_partition_var:
-          print("Models containing partition variables cannot be converted "
-                "from checkpoint files. Please pass in a SavedModel using "
-                "the flag --input_saved_model_dir.")
-          return -1
+          raise ValueError(
+              "Models containing partition variables cannot be converted "
+              "from checkpoint files. Please pass in a SavedModel using "
+              "the flag --input_saved_model_dir.")
         # Models that have been frozen previously do not contain Variables.
         elif _has_no_variables(sess):
-          print("No variables were found in this model. It is likely the model "
-                "was frozen previously. You cannot freeze a graph twice.")
+          raise ValueError(
+              "No variables were found in this model. It is likely the model "
+              "was frozen previously. You cannot freeze a graph twice.")
           return 0
         else:
           raise e
@@ -242,8 +243,7 @@ def freeze_graph_with_def_protos(input_graph_def,
 def _parse_input_graph_proto(input_graph, input_binary):
   """Parses input tensorflow graph into GraphDef proto."""
   if not gfile.Exists(input_graph):
-    print("Input graph file '" + input_graph + "' does not exist!")
-    return -1
+    raise IOError("Input graph file '" + input_graph + "' does not exist!")
   input_graph_def = graph_pb2.GraphDef()
   mode = "rb" if input_binary else "r"
   with gfile.GFile(input_graph, mode) as f:
@@ -257,8 +257,7 @@ def _parse_input_graph_proto(input_graph, input_binary):
 def _parse_input_meta_graph_proto(input_graph, input_binary):
   """Parses input tensorflow graph into MetaGraphDef proto."""
   if not gfile.Exists(input_graph):
-    print("Input meta graph file '" + input_graph + "' does not exist!")
-    return -1
+    raise IOError("Input meta graph file '" + input_graph + "' does not exist!")
   input_meta_graph_def = MetaGraphDef()
   mode = "rb" if input_binary else "r"
   with gfile.GFile(input_graph, mode) as f:
@@ -273,8 +272,7 @@ def _parse_input_meta_graph_proto(input_graph, input_binary):
 def _parse_input_saver_proto(input_saver, input_binary):
   """Parses input tensorflow Saver into SaverDef proto."""
   if not gfile.Exists(input_saver):
-    print("Input saver file '" + input_saver + "' does not exist!")
-    return -1
+    raise IOError("Input saver file '" + input_saver + "' does not exist!")
   mode = "rb" if input_binary else "r"
   with gfile.GFile(input_saver, mode) as f:
     saver_def = saver_pb2.SaverDef()
@@ -369,9 +367,8 @@ def main(unused_args, flags):
   elif flags.checkpoint_version == 2:
     checkpoint_version = saver_pb2.SaverDef.V2
   else:
-    print("Invalid checkpoint version (must be '1' or '2'): %d" %
-          flags.checkpoint_version)
-    return -1
+    raise ValueError("Invalid checkpoint version (must be '1' or '2'): %d" %
+                     flags.checkpoint_version)
   freeze_graph(flags.input_graph, flags.input_saver, flags.input_binary,
                flags.input_checkpoint, flags.output_node_names,
                flags.restore_op_name, flags.filename_tensor_name,
@@ -380,7 +377,9 @@ def main(unused_args, flags):
                flags.input_meta_graph, flags.input_saved_model_dir,
                flags.saved_model_tags, checkpoint_version)
 
+
 def run_main():
+  """Main function of freeze_graph."""
   parser = argparse.ArgumentParser()
   parser.register("type", "bool", lambda v: v.lower() == "true")
   parser.add_argument(
@@ -487,5 +486,6 @@ def run_main():
   my_main = lambda unused_args: main(unused_args, flags)
   app.run(main=my_main, argv=[sys.argv[0]] + unparsed)
 
-if __name__ == '__main__':
+
+if __name__ == "__main__":
   run_main()
diff --git a/tensorflow/python/tools/freeze_graph_test.py b/tensorflow/python/tools/freeze_graph_test.py
index d7edf4ec65d..0d054c00d33 100644
--- a/tensorflow/python/tools/freeze_graph_test.py
+++ b/tensorflow/python/tools/freeze_graph_test.py
@@ -316,17 +316,17 @@ class FreezeGraphTest(test_util.TensorFlowTestCase):
     output_node_names = "save/restore_all"
     output_graph_path = os.path.join(self.get_temp_dir(), output_graph_name)
 
-    return_value = freeze_graph.freeze_graph_with_def_protos(
-        input_graph_def=sess.graph_def,
-        input_saver_def=None,
-        input_checkpoint=checkpoint_path,
-        output_node_names=output_node_names,
-        restore_op_name="save/restore_all",  # default value
-        filename_tensor_name="save/Const:0",  # default value
-        output_graph=output_graph_path,
-        clear_devices=False,
-        initializer_nodes="")
-    self.assertTrue(return_value, -1)
+    with self.assertRaises(ValueError):
+      freeze_graph.freeze_graph_with_def_protos(
+          input_graph_def=sess.graph_def,
+          input_saver_def=None,
+          input_checkpoint=checkpoint_path,
+          output_node_names=output_node_names,
+          restore_op_name="save/restore_all",  # default value
+          filename_tensor_name="save/Const:0",  # default value
+          output_graph=output_graph_path,
+          clear_devices=False,
+          initializer_nodes="")
 
 
 if __name__ == "__main__":
diff --git a/tensorflow/tools/api/golden/v1/tensorflow.lite.experimental.pbtxt b/tensorflow/tools/api/golden/v1/tensorflow.lite.experimental.pbtxt
index 354a7086d60..e4250ac75d4 100644
--- a/tensorflow/tools/api/golden/v1/tensorflow.lite.experimental.pbtxt
+++ b/tensorflow/tools/api/golden/v1/tensorflow.lite.experimental.pbtxt
@@ -8,4 +8,8 @@ tf_module {
     name: "convert_op_hints_to_stubs"
     argspec: "args=[\'session\', \'graph_def\', \'write_callback\'], varargs=None, keywords=None, defaults=[\'None\', \'None\', \'<function <lambda> instance>\'], "
   }
+  member_method {
+    name: "get_potentially_supported_ops"
+    argspec: "args=[], varargs=None, keywords=None, defaults=None"
+  }
 }
diff --git a/tensorflow/tools/api/golden/v2/tensorflow.lite.experimental.pbtxt b/tensorflow/tools/api/golden/v2/tensorflow.lite.experimental.pbtxt
index 354a7086d60..e4250ac75d4 100644
--- a/tensorflow/tools/api/golden/v2/tensorflow.lite.experimental.pbtxt
+++ b/tensorflow/tools/api/golden/v2/tensorflow.lite.experimental.pbtxt
@@ -8,4 +8,8 @@ tf_module {
     name: "convert_op_hints_to_stubs"
     argspec: "args=[\'session\', \'graph_def\', \'write_callback\'], varargs=None, keywords=None, defaults=[\'None\', \'None\', \'<function <lambda> instance>\'], "
   }
+  member_method {
+    name: "get_potentially_supported_ops"
+    argspec: "args=[], varargs=None, keywords=None, defaults=None"
+  }
 }