plotly · brandonschabell · Oct 3, 2026
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -19,6 +19,7 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 
 ### Removed
 - [#3646](https://github.com/plotly/dash/pull/3646) Remove React 16 support (`16.14.0` is no longer an accepted value for `REACT_VERSION` / `_set_react_version`).
+- [#4039](https://github.com/plotly/dash/pull/4039) Remove unnecessary Python version checks (pre 3.9).
 
 ### Changed
 - [#3987](https://github.com/plotly/dash/pull/3987) Forward FastAPI reload scope options (`reload_dirs`, `reload_excludes`, and `reload_includes`) to Uvicorn when reloading.

diff --git a/components/dash-core-components/tests/integration/store/test_store_data.py b/components/dash-core-components/tests/integration/store/test_store_data.py
@@ -1,4 +1,3 @@
-import sys
 import json
 import hashlib
 import itertools
@@ -120,10 +119,6 @@ def on_ts(ts, data):
     assert dash_dcc.get_logs() == []
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 6),
-    reason="tests requires dependency only available in 3.6+",
-)
 @pytest.mark.parametrize("storage_type", ("memory", "local", "session"))
 def test_stda003_large_data_size(storage_type, csv_5mb, dash_dcc):
     def fingerprint(data):

diff --git a/dash/_hooks.py b/dash/_hooks.py
@@ -2,8 +2,6 @@
 
 from importlib import metadata as _importlib_metadata
 
-import typing_extensions as _tx
-
 from .exceptions import HookError
 from .resources import ResourceType
 from ._callback import ClientsideFuncType
@@ -20,12 +18,12 @@
     Dash = None
 
 
-HookDataType = _tx.TypeVar("HookDataType")
-DevtoolPosition = _tx.Literal["right", "left"]
+HookDataType = _t.TypeVar("HookDataType")
+DevtoolPosition = _t.Literal["right", "left"]
 
 
 # pylint: disable=too-few-public-methods
-class _Hook(_tx.Generic[HookDataType]):
+class _Hook(_t.Generic[HookDataType]):
     def __init__(
         self, func, priority=0, final=False, data: _t.Optional[HookDataType] = None
     ):

diff --git a/dash/_jupyter.py b/dash/_jupyter.py
@@ -9,8 +9,7 @@
 import threading
 import time
 
-from typing import Optional, Any
-from typing_extensions import Literal
+from typing import Optional, Any, Literal
 
 from werkzeug.serving import make_server
 

diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
@@ -173,10 +173,7 @@ def generate_components(
 
 
 def safe_json_loads(s):
-    jsondata_unicode = json.loads(s, object_pairs_hook=OrderedDict)
-    if sys.version_info[0] >= 3:
-        return jsondata_unicode
-    return byteify(jsondata_unicode)
+    return json.loads(s, object_pairs_hook=OrderedDict)
 
 
 def component_build_arg_parser():
@@ -282,18 +279,5 @@ def cli():
     )
 
 
-# pylint: disable=undefined-variable
-def byteify(input_object):
-    if isinstance(input_object, dict):
-        return OrderedDict(
-            [(byteify(key), byteify(value)) for key, value in input_object.items()]
-        )
-    if isinstance(input_object, list):
-        return [byteify(element) for element in input_object]
-    if isinstance(input_object, str):  # noqa:F821
-        return input_object.encode(encoding="utf-8")
-    return input_object
-
-
 if __name__ == "__main__":
     cli()
diff --git a/dash/mcp/primitives/tools/tool_get_dash_component.py b/dash/mcp/primitives/tools/tool_get_dash_component.py
@@ -3,10 +3,10 @@
 from __future__ import annotations
 
 import json
-from typing import Any
+from typing import Annotated, Any
 
 from pydantic import Field, TypeAdapter
-from typing_extensions import Annotated, NotRequired, TypedDict
+from typing_extensions import NotRequired, TypedDict
 
 from dash import get_app
 from dash._layout_utils import find_component

diff --git a/dash/resources.py b/dash/resources.py
@@ -3,14 +3,13 @@
 import os
 
 import typing as _t
-import typing_extensions as _tx
 
 
 from .development.base_component import ComponentRegistry
 from . import exceptions
 
 # ResourceType has `async` key, use the init form to be able to provide it.
-ResourceType = _tx.TypedDict(
+ResourceType = _t.TypedDict(
     "ResourceType",
     {
         "namespace": str,

diff --git a/dash/types.py b/dash/types.py
@@ -1,9 +1,9 @@
 import typing
-from typing import Any, Dict, List, Union
+from typing import Annotated, Any, Dict, List, Union
 
 from pydantic import Field, GetCoreSchemaHandler, GetJsonSchemaHandler
 from pydantic_core import core_schema
-from typing_extensions import Annotated, TypedDict, NotRequired
+from typing_extensions import TypedDict, NotRequired
 
 
 class _NumberSchema:  # pylint: disable=too-few-public-methods

diff --git a/requirements/ci.txt b/requirements/ci.txt
@@ -22,5 +22,5 @@ xlrd>=2.0.1
 pytest-rerunfailures
 pytest-timeout
 jupyterlab<4.0.0
-pyright==1.1.411;python_version>="3.7"
+pyright==1.1.411
 mypy==1.15.0;python_version>="3.12"
diff --git a/tests/async_tests/test_async_background_callbacks.py b/tests/async_tests/test_async_background_callbacks.py
@@ -1,8 +1,6 @@
-import sys
 import time
 from multiprocessing import Lock
 
-import pytest
 from flaky import flaky
 
 from tests.utils import is_dash_async
@@ -34,9 +32,6 @@ def test_001ab_arbitrary(dash_duo, manager):
         dash_duo.wait_for_text_to_equal("#no-output", "completed")
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 7), reason="Python 3.6 long callbacks tests hangs up"
-)
 @flaky(max_runs=3)
 def test_002ab_basic(dash_duo, manager):
     """

diff --git a/tests/background_callback/test_basic_long_callback001.py b/tests/background_callback/test_basic_long_callback001.py
@@ -1,15 +1,10 @@
-import sys
 from multiprocessing import Lock
 
-import pytest
 from flaky import flaky
 
 from .utils import setup_background_callback_app
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 7), reason="Python 3.6 long callbacks tests hangs up"
-)
 @flaky(max_runs=3)
 def test_lcbc001_fast_input(dash_duo, manager):
     """

diff --git a/tests/background_callback/test_basic_long_callback002.py b/tests/background_callback/test_basic_long_callback002.py
@@ -1,14 +1,8 @@
-import sys
-
-import pytest
 from flaky import flaky
 
 from tests.background_callback.utils import setup_background_callback_app
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 7), reason="Python 3.6 long callbacks tests hangs up"
-)
 @flaky(max_runs=3)
 def test_lcbc002_long_callback_running(dash_duo, manager):
     with setup_background_callback_app(manager, "app2") as app:

diff --git a/tests/background_callback/test_basic_long_callback003.py b/tests/background_callback/test_basic_long_callback003.py
@@ -1,15 +1,10 @@
-import sys
 from multiprocessing import Lock
 
-import pytest
 from flaky import flaky
 
 from tests.background_callback.utils import setup_background_callback_app
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 7), reason="Python 3.6 long callbacks tests hangs up"
-)
 @flaky(max_runs=3)
 def test_lcbc003_long_callback_running_cancel(dash_duo, manager):
     lock = Lock()

diff --git a/tests/background_callback/test_basic_long_callback004.py b/tests/background_callback/test_basic_long_callback004.py
@@ -1,14 +1,8 @@
-import sys
-
-import pytest
 from flaky import flaky
 
 from tests.background_callback.utils import setup_background_callback_app
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 7), reason="Python 3.6 long callbacks tests hangs up"
-)
 @flaky(max_runs=3)
 def test_lcbc004_long_callback_progress(dash_duo, manager):
     with setup_background_callback_app(manager, "app4") as app:

diff --git a/tests/background_callback/test_basic_long_callback005.py b/tests/background_callback/test_basic_long_callback005.py
@@ -1,14 +1,10 @@
-import sys
 from multiprocessing import Lock
 
 import pytest
 
 from tests.background_callback.utils import setup_background_callback_app
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 7), reason="Python 3.6 long callbacks tests hangs up"
-)
 @pytest.mark.skip(reason="Timeout often")
 def test_lcbc005_long_callback_caching(dash_duo, manager):
     lock = Lock()

diff --git a/tests/background_callback/test_basic_long_callback006.py b/tests/background_callback/test_basic_long_callback006.py
@@ -1,15 +1,10 @@
-import sys
 from multiprocessing import Lock
 
-import pytest
 from flaky import flaky
 
 from tests.background_callback.utils import setup_background_callback_app
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 7), reason="Python 3.6 long callbacks tests hangs up"
-)
 @flaky(max_runs=3)
 def test_lcbc006_long_callback_caching_multi(dash_duo, manager):
     lock = Lock()

diff --git a/tests/background_callback/test_basic_long_callback007.py b/tests/background_callback/test_basic_long_callback007.py
@@ -1,14 +1,8 @@
-import sys
-
-import pytest
 from flaky import flaky
 
 from tests.background_callback.utils import setup_background_callback_app
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 7), reason="Python 3.6 long callbacks tests hangs up"
-)
 @flaky(max_runs=3)
 def test_lcbc007_validation_layout(dash_duo, manager):
     with setup_background_callback_app(manager, "app7") as app:

diff --git a/tests/background_callback/test_basic_long_callback008.py b/tests/background_callback/test_basic_long_callback008.py
@@ -1,13 +1,6 @@
-import sys
-
-import pytest
-
 from tests.background_callback.utils import setup_background_callback_app
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 7), reason="Python 3.6 long callbacks tests hangs up"
-)
 def test_lcbc008_long_callbacks_error(dash_duo, manager):
     with setup_background_callback_app(manager, "app_error") as app:
         dash_duo.start_server(

diff --git a/tests/background_callback/test_basic_long_callback009.py b/tests/background_callback/test_basic_long_callback009.py
@@ -1,14 +1,9 @@
-import sys
 import time
 
-import pytest
 
 from tests.background_callback.utils import setup_background_callback_app
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 7), reason="Python 3.6 long callbacks tests hangs up"
-)
 def test_lcbc009_short_interval(dash_duo, manager):
     with setup_background_callback_app(manager, "app_short_interval") as app:
         dash_duo.start_server(app)

diff --git a/tests/background_callback/test_basic_long_callback010.py b/tests/background_callback/test_basic_long_callback010.py
@@ -1,13 +1,6 @@
-import sys
-
-import pytest
-
 from tests.background_callback.utils import setup_background_callback_app
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 7), reason="Python 3.6 long callbacks tests hangs up"
-)
 def test_lcbc010_side_updates(dash_duo, manager):
     with setup_background_callback_app(manager, "app_side_update") as app:
         dash_duo.start_server(app)

diff --git a/tests/background_callback/test_basic_long_callback011.py b/tests/background_callback/test_basic_long_callback011.py
@@ -1,13 +1,6 @@
-import sys
-
-import pytest
-
 from tests.background_callback.utils import setup_background_callback_app
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 7), reason="Python 3.6 long callbacks tests hangs up"
-)
 def test_lcbc011_long_pattern_matching(dash_duo, manager):
     with setup_background_callback_app(manager, "app_pattern_matching") as app:
         dash_duo.start_server(app)

diff --git a/tests/background_callback/test_basic_long_callback012.py b/tests/background_callback/test_basic_long_callback012.py
@@ -1,14 +1,9 @@
 import json
-import sys
 
-import pytest
 
 from tests.background_callback.utils import setup_background_callback_app
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 7), reason="Python 3.6 long callbacks tests hangs up"
-)
 def test_lcbc012_long_callback_ctx(dash_duo, manager):
     with setup_background_callback_app(manager, "app_callback_ctx") as app:
         dash_duo.start_server(app)

diff --git a/tests/background_callback/test_basic_long_callback013.py b/tests/background_callback/test_basic_long_callback013.py
@@ -1,13 +1,6 @@
-import sys
-
-import pytest
-
 from tests.background_callback.utils import setup_background_callback_app
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 7), reason="Python 3.6 long callbacks tests hangs up"
-)
 def test_lcbc013_unordered_state_input(dash_duo, manager):
     with setup_background_callback_app(manager, "app_unordered") as app:
         dash_duo.start_server(app)

diff --git a/tests/background_callback/test_basic_long_callback014.py b/tests/background_callback/test_basic_long_callback014.py
@@ -1,13 +1,6 @@
-import sys
-
-import pytest
-
 from tests.background_callback.utils import setup_background_callback_app
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 7), reason="Python 3.6 long callbacks tests hangs up"
-)
 def test_lcbc014_progress_delete(dash_duo, manager):
     with setup_background_callback_app(manager, "app_progress_delete") as app:
         dash_duo.start_server(app)

diff --git a/tests/background_callback/test_basic_long_callback015.py b/tests/background_callback/test_basic_long_callback015.py
@@ -1,13 +1,6 @@
-import sys
-
-import pytest
-
 from tests.background_callback.utils import setup_background_callback_app
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 7), reason="Python 3.6 long callbacks tests hangs up"
-)
 def test_lcbc015_diff_outputs_same_func(dash_duo, manager):
     with setup_background_callback_app(manager, "app_diff_outputs") as app:
         dash_duo.start_server(app)

diff --git a/tests/background_callback/test_basic_long_callback016.py b/tests/background_callback/test_basic_long_callback016.py
@@ -1,14 +1,8 @@
-import sys
-
-import pytest
 from flaky import flaky
 
 from tests.background_callback.utils import setup_background_callback_app
 
 
-@pytest.mark.skipif(
-    sys.version_info < (3, 9), reason="Python 3.8 long callbacks tests hangs up"
-)
 @flaky(max_runs=3)
 def test_lcbc016_multi_page_cancel(dash_duo, manager):
     with setup_background_callback_app(manager, "app_page_cancel") as app: