diff --git a/jaxonnxruntime/__init__.py b/jaxonnxruntime/__init__.py
index fe5349f..438a393 100644
--- a/jaxonnxruntime/__init__.py
+++ b/jaxonnxruntime/__init__.py
@@ -61,6 +61,7 @@
 from jaxonnxruntime.onnx_ops import globalaveragepool
 from jaxonnxruntime.onnx_ops import greater
 from jaxonnxruntime.onnx_ops import greaterorequal
+from jaxonnxruntime.onnx_ops import hardsigmoid
 from jaxonnxruntime.onnx_ops import identity
 from jaxonnxruntime.onnx_ops import if_op
 from jaxonnxruntime.onnx_ops import leakyrelu
@@ -90,6 +91,7 @@
 from jaxonnxruntime.onnx_ops import reducesum
 from jaxonnxruntime.onnx_ops import relu
 from jaxonnxruntime.onnx_ops import reshape
+from jaxonnxruntime.onnx_ops import resize
 from jaxonnxruntime.onnx_ops import scatterelements
 from jaxonnxruntime.onnx_ops import scatternd
 from jaxonnxruntime.onnx_ops import selu
diff --git a/jaxonnxruntime/core/handler.py b/jaxonnxruntime/core/handler.py
index 161e4d0..4f7374b 100644
--- a/jaxonnxruntime/core/handler.py
+++ b/jaxonnxruntime/core/handler.py
@@ -80,21 +80,28 @@ def handle(
     Returns:
       The jax function.
     """
-    ver_handle = getattr(cls, "version_{}".format(cls.SINCE_VERSION), None)
-    if ver_handle:
-      return ver_handle(node, inputs, **kwargs)  # pylint: disable=not-callable
-
     # Get all the methods that start with "version_"
     class_methods = inspect.getmembers(cls, predicate=inspect.ismethod)
-    version_methods = [
-        method_name
-        for method_name, _ in class_methods
+    version_methods = {
+        int(method_name.split("_")[1]): method
+        for method_name, method in class_methods
         if method_name.startswith("version_")
-    ]
+    }
+
+    if not version_methods:
+      raise NotImplementedError(
+          f"{node.op_type} has no versioned implementations."
+      )
+
+    # Find the largest version which is <= cls.SINCE_VERSION
+    available_versions = sorted(version_methods.keys(), reverse=True)
+    for v in available_versions:
+      if v <= cls.SINCE_VERSION:
+        return version_methods[v](node, inputs, **kwargs)
 
     raise NotImplementedError(
         f"{node.op_type} version {cls.SINCE_VERSION} is not implemented."
-        f" Only have those versions: {version_methods}."
+        f" Only have those versions: {sorted(version_methods.keys())}."
     )
 
   @classmethod
@@ -104,7 +111,13 @@ def _prepare(
       inputs: Sequence[Any],
       onnx_jax_impl: Callable[..., Any],
   ) -> None:
-    """Rwrite the OnnxNode to prepare the inputs attributes for the onnx jax implementation."""
+    """Rwrite the OnnxNode to prepare the inputs attributes.
+
+    Args:
+      node: The onnx node to be handled.
+      inputs: The inputs of the onnx node.
+      onnx_jax_impl: The jax function for the onnx op.
+    """
     raise NotImplementedError
 
 
diff --git a/jaxonnxruntime/onnx_ops/clip.py b/jaxonnxruntime/onnx_ops/clip.py
index 2aed467..1c98070 100644
--- a/jaxonnxruntime/onnx_ops/clip.py
+++ b/jaxonnxruntime/onnx_ops/clip.py
@@ -32,16 +32,22 @@ class Clip(handler.Handler):
   @classmethod
   def _prepare_6(
       cls, node: onnx_node.OnnxNode, inputs: Sequence[Any], onnx_jax_impl: Any
-  ):
+  ) -> None:
     node.attrs_dict['amin'] = node.attrs.get('min')
     node.attrs_dict['amax'] = node.attrs.get('max')
 
   @classmethod
   def _prepare_13(
       cls, node: onnx_node.OnnxNode, inputs: Sequence[Any], onnx_jax_impl: Any
-  ):
+  ) -> None:
     pass
 
+  @classmethod
+  def _prepare(
+      cls, node: onnx_node.OnnxNode, inputs: Sequence[Any], onnx_jax_impl: Any
+  ) -> None:
+    cls._prepare_13(node, inputs, onnx_jax_impl)
+
   @classmethod
   def version_6(
       cls, node: onnx_node.OnnxNode, inputs: Sequence[Any]
@@ -50,6 +56,14 @@ def version_6(
     cls._prepare_6(node, inputs, onnx_clip)
     return onnx_clip
 
+  @classmethod
+  def version_11(
+      cls, node: onnx_node.OnnxNode, inputs: Sequence[Any]
+  ) -> Callable[..., Any]:
+    """ONNX version_11 Clip op."""
+    cls._prepare_13(node, inputs, onnx_clip)
+    return onnx_clip
+
   @classmethod
   def version_13(
       cls, node: onnx_node.OnnxNode, inputs: Sequence[Any]
@@ -60,8 +74,14 @@ def version_13(
 
 
 @functools.partial(jax.jit, static_argnames=())
-def onnx_clip(data, amin=None, amax=None):
-  """https://github.com/onnx/onnx/blob/v1.12.0/docs/Operators.md#Clip for more details."""
+def onnx_clip(*input_args: jax.Array, amin=None, amax=None) -> jax.Array:
+  """The impl for Clip operator."""
+  data = input_args[0]
+  if len(input_args) >= 2:
+    amin = input_args[1]
+  if len(input_args) >= 3:
+    amax = input_args[2]
+
   if amin is None and amax is None:
     return data
-  return jnp.clip(data, min=amin, max=amax)
+  return jnp.clip(data, a_min=amin, a_max=amax)
diff --git a/jaxonnxruntime/onnx_ops/hardsigmoid.py b/jaxonnxruntime/onnx_ops/hardsigmoid.py
new file mode 100644
index 0000000..092c360
--- /dev/null
+++ b/jaxonnxruntime/onnx_ops/hardsigmoid.py
@@ -0,0 +1,64 @@
+# Copyright 2025 The Jaxonnxruntime Authors.
+#
+# 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.
+"""Define ONNX HardSigmoid operator."""
+from collections.abc import Callable, Sequence
+import functools
+import inspect
+from typing import Any
+
+import jax
+from jax import jit
+from jax import numpy as jnp
+from jaxonnxruntime.core import handler
+from jaxonnxruntime.core import onnx_node
+
+
+@handler.register_op("HardSigmoid")
+class HardSigmoid(handler.Handler):
+  """Implementation of the ONNX HardSigmoid operator."""
+
+  @classmethod
+  def _prepare(
+      cls, node: onnx_node.OnnxNode, inputs: Sequence[Any], onnx_jax_impl: Any
+  ) -> None:
+    sig = inspect.signature(onnx_jax_impl)
+    kwparams = [
+        param.name
+        for param in sig.parameters.values()
+        if param.kind == inspect.Parameter.KEYWORD_ONLY
+    ]
+    for name in kwparams:
+      node.attrs_dict[name] = node.attrs.get(name, None)
+
+  @classmethod
+  def version_6(
+      cls, node: onnx_node.OnnxNode, inputs: Sequence[Any]
+  ) -> Callable[..., Any]:
+    """ONNX version_6 HardSigmoid op."""
+    cls._prepare(node, inputs, onnx_hardsigmoid)
+    return onnx_hardsigmoid
+
+
+@functools.partial(jit, static_argnames=("alpha", "beta"))
+def onnx_hardsigmoid(
+    *input_args: jax.Array, alpha: float = 0.2, beta: float = 0.5
+) -> jax.Array:
+  """The internal jax impl for onnx HardSigmoid op."""
+  assert len(input_args) == 1
+  x = input_args[0]
+  if alpha is None:
+    alpha = 0.2
+  if beta is None:
+    beta = 0.5
+  return jnp.clip(alpha * x + beta, 0.0, 1.0)
diff --git a/jaxonnxruntime/onnx_ops/reducesum.py b/jaxonnxruntime/onnx_ops/reducesum.py
index 8338980..a79f83e 100644
--- a/jaxonnxruntime/onnx_ops/reducesum.py
+++ b/jaxonnxruntime/onnx_ops/reducesum.py
@@ -63,6 +63,14 @@ def version_1(
     cls._prepare(node, inputs, onnx_reducesum)
     return onnx_reducesum
 
+  @classmethod
+  def version_11(
+      cls, node: onnx_node.OnnxNode, inputs: Sequence[Any]
+  ) -> Callable[..., Any]:
+    """ONNX version_11 ReduceSum op."""
+    cls._prepare(node, inputs, onnx_reducesum)
+    return onnx_reducesum
+
   @classmethod
   def version_13(
       cls, node: onnx_node.OnnxNode, inputs: Sequence[Any]
@@ -81,7 +89,7 @@ def onnx_reducesum(
     keepdims=1,
     noop_with_empty_axes=0,
 ):
-  """The impl for https://github.com/onnx/onnx/blob/v1.12.0/docs/Operators.md#ReduceSum."""
+  """The impl for ReduceSum operator."""
   assert len(input_args) == 1 or len(input_args) == 2
   data = input_args[0]
   if axes is None and noop_with_empty_axes > 0:
diff --git a/jaxonnxruntime/onnx_ops/resize.py b/jaxonnxruntime/onnx_ops/resize.py
new file mode 100644
index 0000000..ddf698f
--- /dev/null
+++ b/jaxonnxruntime/onnx_ops/resize.py
@@ -0,0 +1,122 @@
+# Copyright 2025 The Jaxonnxruntime Authors.
+#
+# 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.
+
+"""Define ONNX Resize operator."""
+from collections.abc import Callable, Sequence
+import functools
+from typing import Any
+import jax
+from jax import numpy as jnp
+from jaxonnxruntime.core import config_class
+
+config = config_class.config
+from jaxonnxruntime.core import handler
+from jaxonnxruntime.core import onnx_node
+import numpy as np
+
+
+@handler.register_op('Resize')
+class Resize(handler.Handler):
+  """Implementation of the ONNX Resize operator."""
+
+  @classmethod
+  def _prepare(
+      cls, node: onnx_node.OnnxNode, inputs: Sequence[Any], onnx_jax_impl: Any
+  ):
+    # Extract attributes
+    # attrs are already strings in this jaxonnxruntime version
+    mode = node.attrs.get('mode', 'nearest')
+    if isinstance(mode, bytes):
+        mode = mode.decode('utf-8')
+    node.attrs_dict['mode'] = mode
+    
+    coordinate_transformation_mode = node.attrs.get('coordinate_transformation_mode', 'half_pixel')
+    if isinstance(coordinate_transformation_mode, bytes):
+        coordinate_transformation_mode = coordinate_transformation_mode.decode('utf-8')
+    node.attrs_dict['coordinate_transformation_mode'] = coordinate_transformation_mode
+    
+    # Resize has inputs: X, roi, scales, sizes
+    # We need to determine target 'sizes'
+    if len(inputs) >= 4 and inputs[3] is not None:
+        node.attrs_dict['sizes'] = tuple(inputs[3].astype(int).tolist())
+    elif len(inputs) >= 3 and inputs[2] is not None:
+        scales = inputs[2]
+        x_shape = inputs[0].shape
+        sizes = [int(x_shape[i] * scales[i]) for i in range(len(x_shape))]
+        node.attrs_dict['sizes'] = tuple(sizes)
+    else:
+        # Fallback: check if sizes/scales are in constant dict
+        constant_dict = node.context_graph.get_constant_dict()
+        if len(node.inputs) >= 4 and node.inputs[3] in constant_dict:
+             node.attrs_dict['sizes'] = tuple(constant_dict[node.inputs[3]].astype(int).tolist())
+        elif len(node.inputs) >= 3 and node.inputs[2] in constant_dict:
+             scales = constant_dict[node.inputs[2]]
+             x_shape = inputs[0].shape
+             sizes = [int(x_shape[i] * scales[i]) for i in range(len(x_shape))]
+             node.attrs_dict['sizes'] = tuple(sizes)
+        else:
+             # If still not found, we might have to wait for runtime shape or it's a dynamic resize.
+             # However, for JAX, we prefer static sizes.
+             raise ValueError(f"Resize node {node.name} needs valid 'scales' or 'sizes'.")
+
+  @classmethod
+  def version_10(
+      cls, node: onnx_node.OnnxNode, inputs: Sequence[Any]
+  ) -> Callable[..., Any]:
+    """ONNX version_10 Resize op."""
+    cls._prepare(node, inputs, onnx_resize)
+    return onnx_resize
+
+  @classmethod
+  def version_11(
+      cls, node: onnx_node.OnnxNode, inputs: Sequence[Any]
+  ) -> Callable[..., Any]:
+    """ONNX version_11 Resize op."""
+    cls._prepare(node, inputs, onnx_resize)
+    return onnx_resize
+
+  @classmethod
+  def version_13(
+      cls, node: onnx_node.OnnxNode, inputs: Sequence[Any]
+  ) -> Callable[..., Any]:
+    """ONNX version_13 Resize op."""
+    cls._prepare(node, inputs, onnx_resize)
+    return onnx_resize
+
+  @classmethod
+  def version_18(
+      cls, node: onnx_node.OnnxNode, inputs: Sequence[Any]
+  ) -> Callable[..., Any]:
+    """ONNX version_18 Resize op."""
+    cls._prepare(node, inputs, onnx_resize)
+    return onnx_resize
+
+
+@functools.partial(jax.jit, static_argnames=('sizes', 'mode', 'coordinate_transformation_mode'))
+def onnx_resize(*input_args, sizes, mode, coordinate_transformation_mode):
+  """The impl for Resize."""
+  x = input_args[0]
+  
+  # Map ONNX modes to JAX modes
+  # ONNX modes: 'nearest', 'linear', 'cubic'
+  # JAX modes: 'nearest', 'linear', 'bilinear', 'trilinear', 'cubic', 'lanczos3', 'lanczos5'
+  jax_method = mode
+  if jax_method == 'linear':
+      # If rank is 4 (N, C, H, W), 'bilinear' is more appropriate for 2D spatial resize
+      if x.ndim == 4:
+          jax_method = 'bilinear'
+      else:
+          jax_method = 'linear'
+  
+  return jax.image.resize(x, shape=sizes, method=jax_method)
diff --git a/jaxonnxruntime/onnx_ops/squeeze.py b/jaxonnxruntime/onnx_ops/squeeze.py
index a08f9e0..a817435 100644
--- a/jaxonnxruntime/onnx_ops/squeeze.py
+++ b/jaxonnxruntime/onnx_ops/squeeze.py
@@ -45,7 +45,7 @@ def _prepare(
       cls, node: onnx_node.OnnxNode, inputs: Sequence[Any], onnx_jax_impl: Any
   ):
     if len(inputs) == 1:
-      node.attrs_dict['axis'] = None
+      node.attrs_dict['axis'] = node.attrs.get('axes', None)
     else:
       node.attrs_dict['axis'] = tuple(inputs[1].tolist())
 
@@ -76,6 +76,6 @@ def version_13(
 
 @functools.partial(jax.jit, static_argnames='axis')
 def onnx_squeeze(*input_args, axis):
-  """The impl for https://github.com/onnx/onnx/blob/v1.12.0/docs/Operators.md#Squeeze."""
+  """The impl for Squeeze operator."""
   x = input_args[0]
   return jnp.squeeze(x, axis=axis)
diff --git a/tests/onnx_ops_test.py b/tests/onnx_ops_test.py
index 33e21b8..0edf2c7 100644
--- a/tests/onnx_ops_test.py
+++ b/tests/onnx_ops_test.py
@@ -106,6 +106,7 @@ class NodeTest(absltest.TestCase):
 include_patterns.append('test_globalaveragepool_')
 include_patterns.append('test_greater_')
 include_patterns.append('test_greaterorequal_')
+include_patterns.append('test_hardsigmoid_')
 include_patterns.append('test_identity_')
 include_patterns.append('test_if_')
 include_patterns.append('test_leakyrelu_')
@@ -133,6 +134,7 @@ class NodeTest(absltest.TestCase):
 include_patterns.append('test_reduce_sum_')
 include_patterns.append('test_relu_')
 include_patterns.append('test_reshape_')
+include_patterns.append('test_resize_')
 include_patterns.append('test_scatter_elements_')
 include_patterns.append('test_scatternd_')
 include_patterns.append('test_selu_')
@@ -251,6 +253,15 @@ class NodeTest(absltest.TestCase):
     'test_training_dropout_default_',
     'test_training_dropout_default_mask_',
     'test_training_dropout_mask_',
+    # Resize: Needs full spec implementation for coordinate transformations and rounding
+    'test_resize_downsample_',
+    'test_resize_tf_crop_',
+    'test_resize_upsample_scales_cubic_align_corners_',
+    'test_resize_upsample_scales_cubic_asymmetric_',
+    'test_resize_upsample_scales_cubic_gpu',
+    'test_resize_upsample_scales_linear_align_corners_',
+    'test_resize_upsample_scales_linear_half_pixel_symmetric_',
+    'test_resize_upsample_sizes_',
 ])