diff --git a/labelme/__init__.py b/labelme/__init__.py
index a544e969a..0f3b158d7 100644
--- a/labelme/__init__.py
+++ b/labelme/__init__.py
@@ -1,7 +1,6 @@
 # flake8: noqa
 
 import logging
-import sys
 
 from qtpy import QT_VERSION
 
@@ -19,10 +18,6 @@
 QT5 = QT_VERSION[0] == "5"
 del QT_VERSION
 
-PY2 = sys.version[0] == "2"
-PY3 = sys.version[0] == "3"
-del sys
-
 from labelme.label_file import LabelFile
 from labelme import testing
 from labelme import utils
diff --git a/labelme/app.py b/labelme/app.py
index 7bbce4936..9238bbcf2 100644
--- a/labelme/app.py
+++ b/labelme/app.py
@@ -16,7 +16,6 @@
 from qtpy import QtWidgets
 from qtpy.QtCore import Qt
 
-from labelme import PY2
 from labelme import __appname__
 from labelme import ai
 from labelme.ai import MODELS
@@ -1429,7 +1428,7 @@ def format_shape(s):
             data = s.other_data.copy()
             data.update(
                 dict(
-                    label=s.label.encode("utf-8") if PY2 else s.label,
+                    label=s.label,
                     points=[(p.x(), p.y()) for p in s.points],
                     group_id=s.group_id,
                     description=s.description,
diff --git a/labelme/cli/draw_json.py b/labelme/cli/draw_json.py
index 0ad3389f4..9bedf8c22 100644
--- a/labelme/cli/draw_json.py
+++ b/labelme/cli/draw_json.py
@@ -1,7 +1,6 @@
 #!/usr/bin/env python
 
 import argparse
-import sys
 
 import imgviz
 import matplotlib.pyplot as plt
@@ -9,8 +8,6 @@
 from labelme import utils
 from labelme.label_file import LabelFile
 
-PY2 = sys.version_info[0] == 2
-
 
 def main():
     parser = argparse.ArgumentParser()
diff --git a/labelme/label_file.py b/labelme/label_file.py
index 3c1f31530..36b0aa938 100644
--- a/labelme/label_file.py
+++ b/labelme/label_file.py
@@ -6,8 +6,6 @@
 
 import PIL.Image
 
-from labelme import PY2
-from labelme import QT4
 from labelme import __version__
 from labelme import utils
 from labelme.logger import logger
@@ -18,12 +16,7 @@
 @contextlib.contextmanager
 def open(name, mode):
     assert mode in ["r", "w"]
-    if PY2:
-        mode += "b"
-        encoding = None
-    else:
-        encoding = "utf-8"
-    yield io.open(name, mode, encoding=encoding)
+    yield io.open(name, mode, encoding="utf-8")
     return
 
 
@@ -55,9 +48,7 @@ def load_image_file(filename):
 
         with io.BytesIO() as f:
             ext = osp.splitext(filename)[1].lower()
-            if PY2 and QT4:
-                format = "PNG"
-            elif ext in [".jpg", ".jpeg"]:
+            if ext in [".jpg", ".jpeg"]:
                 format = "JPEG"
             else:
                 format = "PNG"
@@ -90,8 +81,6 @@ def load(self, filename):
 
             if data["imageData"] is not None:
                 imageData = base64.b64decode(data["imageData"])
-                if PY2 and QT4:
-                    imageData = utils.img_data_to_png_data(imageData)
             else:
                 # relative path from label file to relative path from cwd
                 imagePath = osp.join(osp.dirname(filename), data["imagePath"])