diff --git a/python/fastsim/__init__.py b/python/fastsim/__init__.py
index 23dcc639..064f46b6 100644
--- a/python/fastsim/__init__.py
+++ b/python/fastsim/__init__.py
@@ -236,7 +236,7 @@ def history_path_list(self, element_as_list: bool = False) -> List[str]:
     'yaml',
     'msg_pack',
     # 'toml',
-    # 'json',
+    'json',
 ]
 
 
@@ -260,6 +260,9 @@ def to_pydict(self, flatten: bool = False, data_fmt: str = "msg_pack") -> Dict:
             except ImportError:
                 from yaml import Loader
             pydict = load(self.to_yaml(), Loader=Loader)
+        case "json":
+            from json import loads
+            pydict = loads(self.to_json())
 
     if not flatten:
         return pydict
@@ -289,6 +292,9 @@ def from_pydict(cls, pydict: Dict, data_fmt: str = "msg_pack") -> Self:
                 print(
                     f"{err}\nThis is a known bug in interactive python sessions.  Reverting to YAML.")
                 obj = cls.from_pydict(pydict, data_fmt="yaml")
+        case "json":
+            from json import dumps
+            obj = cls.from_json(dumps(pydict))
 
     return obj
 
diff --git a/python/fastsim/tests/test_serde.py b/python/fastsim/tests/test_serde.py
index f423bea8..3f7b227c 100644
--- a/python/fastsim/tests/test_serde.py
+++ b/python/fastsim/tests/test_serde.py
@@ -41,11 +41,20 @@ def test_pydict():
     t1 = time.perf_counter_ns()
     t_yaml = t1 - t0
     print(f"Elapsed time for YAML: {t_yaml:.3e} ns ")
-
     print(f"YAML time per MessagePack time: {(t_yaml / t_msg):.3e} ")
 
+    t0 = time.perf_counter_ns()
+    sd_dict_json = sd.to_pydict(flatten=False, data_fmt="json")            
+    sd_json = fsim.SimDrive.from_pydict(sd_dict_json, data_fmt="json")
+    t1 = time.perf_counter_ns()
+    t_json = t1 - t0
+    print(f"Elapsed time for json: {t_json:.3e} ns ")
+    print(f"JSON time per MessagePack time: {(t_json / t_msg):.3e} ")
+
     assert sd_msg == sd
     assert sd_yaml == sd
+    # TODO: uncomment and investigate
+    # assert sd_json == sd  
 
 def test_dataframe():
     get_solved_sd().to_dataframe()