diff --git a/src/replicate/lib/_files.py b/src/replicate/lib/_files.py
index ad49a4c..04a17c3 100644
--- a/src/replicate/lib/_files.py
+++ b/src/replicate/lib/_files.py
@@ -19,6 +19,30 @@
 FileEncodingStrategy = Literal["base64", "url"]
 
 
+def filter_none_values(obj: Any) -> Any:  # noqa: ANN401
+    """
+    Recursively filter out None values from dictionaries.
+
+    This preserves the legacy behavior where None-valued inputs are removed
+    before making API requests.
+
+    Args:
+        obj: The object to filter.
+
+    Returns:
+        The object with None values removed from all nested dictionaries.
+    """
+    if isinstance(obj, dict):
+        return {
+            key: filter_none_values(value)
+            for key, value in obj.items()  # type: ignore[misc]
+            if value is not None
+        }
+    if isinstance(obj, (list, tuple)):
+        return type(obj)(filter_none_values(item) for item in obj)  # type: ignore[arg-type, misc]
+    return obj
+
+
 try:
     import numpy as np  # type: ignore
 
@@ -35,12 +59,15 @@ def encode_json(
 ) -> Any:  # noqa: ANN401
     """
     Return a JSON-compatible version of the object.
+
+    None values are filtered out from dictionaries to prevent API errors.
     """
 
     if isinstance(obj, dict):
         return {
             key: encode_json(value, client, file_encoding_strategy)
             for key, value in obj.items()  # type: ignore
+            if value is not None
         }  # type: ignore
     if isinstance(obj, (list, set, frozenset, GeneratorType, tuple)):
         return [encode_json(value, client, file_encoding_strategy) for value in obj]  # type: ignore
@@ -70,12 +97,15 @@ async def async_encode_json(
 ) -> Any:  # noqa: ANN401
     """
     Asynchronously return a JSON-compatible version of the object.
+
+    None values are filtered out from dictionaries to prevent API errors.
     """
 
     if isinstance(obj, dict):
         return {
             key: (await async_encode_json(value, client, file_encoding_strategy))
             for key, value in obj.items()  # type: ignore
+            if value is not None
         }  # type: ignore
     if isinstance(obj, (list, set, frozenset, GeneratorType, tuple)):
         return [
diff --git a/src/replicate/resources/deployments/predictions.py b/src/replicate/resources/deployments/predictions.py
index aa22e7d..0f4bac7 100644
--- a/src/replicate/resources/deployments/predictions.py
+++ b/src/replicate/resources/deployments/predictions.py
@@ -17,6 +17,7 @@
     async_to_raw_response_wrapper,
     async_to_streamed_response_wrapper,
 )
+from ...lib._files import filter_none_values
 from ..._base_client import make_request_options
 from ...types.prediction import Prediction
 from ...types.deployments import prediction_create_params
@@ -176,7 +177,7 @@ def create(
             f"/deployments/{deployment_owner}/{deployment_name}/predictions",
             body=maybe_transform(
                 {
-                    "input": input,
+                    "input": filter_none_values(input),
                     "stream": stream,
                     "webhook": webhook,
                     "webhook_events_filter": webhook_events_filter,
@@ -342,7 +343,7 @@ async def create(
             f"/deployments/{deployment_owner}/{deployment_name}/predictions",
             body=await async_maybe_transform(
                 {
-                    "input": input,
+                    "input": filter_none_values(input),
                     "stream": stream,
                     "webhook": webhook,
                     "webhook_events_filter": webhook_events_filter,
diff --git a/src/replicate/resources/trainings.py b/src/replicate/resources/trainings.py
index 51ab733..7f9abbd 100644
--- a/src/replicate/resources/trainings.py
+++ b/src/replicate/resources/trainings.py
@@ -18,6 +18,7 @@
     async_to_raw_response_wrapper,
     async_to_streamed_response_wrapper,
 )
+from ..lib._files import filter_none_values
 from ..pagination import SyncCursorURLPage, AsyncCursorURLPage
 from .._base_client import AsyncPaginator, make_request_options
 from ..types.training_get_response import TrainingGetResponse
@@ -187,7 +188,7 @@ def create(
             body=maybe_transform(
                 {
                     "destination": destination,
-                    "input": input,
+                    "input": filter_none_values(input),
                     "webhook": webhook,
                     "webhook_events_filter": webhook_events_filter,
                 },
@@ -573,7 +574,7 @@ async def create(
             body=await async_maybe_transform(
                 {
                     "destination": destination,
-                    "input": input,
+                    "input": filter_none_values(input),
                     "webhook": webhook,
                     "webhook_events_filter": webhook_events_filter,
                 },
diff --git a/tests/test_filter_none_values.py b/tests/test_filter_none_values.py
new file mode 100644
index 0000000..afabfd0
--- /dev/null
+++ b/tests/test_filter_none_values.py
@@ -0,0 +1,136 @@
+from replicate import Replicate
+from replicate.lib._files import encode_json, async_encode_json, filter_none_values
+
+
+def test_filter_none_values_simple_dict():
+    """Test that None values are filtered from a simple dictionary."""
+    input_dict = {"prompt": "banana", "seed": None, "width": 512}
+    result = filter_none_values(input_dict)
+    assert result == {"prompt": "banana", "width": 512}
+    assert "seed" not in result
+
+
+def test_filter_none_values_nested_dict():
+    """Test that None values are filtered from nested dictionaries."""
+    input_dict = {
+        "prompt": "banana",
+        "config": {"seed": None, "temperature": 0.8, "iterations": None},
+        "width": 512,
+    }
+    result = filter_none_values(input_dict)
+    assert result == {
+        "prompt": "banana",
+        "config": {"temperature": 0.8},
+        "width": 512,
+    }
+    assert "seed" not in result["config"]
+    assert "iterations" not in result["config"]
+
+
+def test_filter_none_values_all_none():
+    """Test that a dict with all None values returns an empty dict."""
+    input_dict = {"seed": None, "temperature": None}
+    result = filter_none_values(input_dict)
+    assert result == {}
+
+
+def test_filter_none_values_empty_dict():
+    """Test that an empty dict returns an empty dict."""
+    input_dict = {}
+    result = filter_none_values(input_dict)
+    assert result == {}
+
+
+def test_filter_none_values_with_list():
+    """Test that lists are preserved and None values in dicts within lists are filtered."""
+    input_dict = {
+        "prompts": ["banana", "apple"],
+        "seeds": [None, 42, None],
+        "config": {"value": None},
+    }
+    result = filter_none_values(input_dict)
+    # None values in lists are preserved
+    assert result == {
+        "prompts": ["banana", "apple"],
+        "seeds": [None, 42, None],
+        "config": {},
+    }
+
+
+def test_filter_none_values_with_tuple():
+    """Test that tuples are preserved."""
+    input_dict = {"coords": (1, None, 3)}
+    result = filter_none_values(input_dict)
+    # Tuples are preserved as-is
+    assert result == {"coords": (1, None, 3)}
+
+
+def test_filter_none_values_non_dict():
+    """Test that non-dict values are returned as-is."""
+    assert filter_none_values("string") == "string"
+    assert filter_none_values(42) == 42
+    assert filter_none_values(None) is None
+    assert filter_none_values([1, 2, 3]) == [1, 2, 3]
+
+
+def test_encode_json_filters_none(client: Replicate):
+    """Test that encode_json filters None values from dicts."""
+    input_dict = {"prompt": "banana", "seed": None, "width": 512}
+    result = encode_json(input_dict, client)
+    assert result == {"prompt": "banana", "width": 512}
+    assert "seed" not in result
+
+
+def test_encode_json_nested_none_filtering(client: Replicate):
+    """Test that encode_json recursively filters None values."""
+    input_dict = {
+        "prompt": "banana",
+        "config": {"seed": None, "temperature": 0.8},
+        "metadata": {"user": "test", "session": None},
+    }
+    result = encode_json(input_dict, client)
+    assert result == {
+        "prompt": "banana",
+        "config": {"temperature": 0.8},
+        "metadata": {"user": "test"},
+    }
+
+
+async def test_async_encode_json_filters_none(async_client):  # type: ignore[no-untyped-def]
+    """Test that async_encode_json filters None values from dicts."""
+    input_dict = {"prompt": "banana", "seed": None, "width": 512}
+    result = await async_encode_json(input_dict, async_client)  # type: ignore[arg-type]
+    assert result == {"prompt": "banana", "width": 512}
+    assert "seed" not in result
+
+
+async def test_async_encode_json_nested_none_filtering(async_client):  # type: ignore[no-untyped-def]
+    """Test that async_encode_json recursively filters None values."""
+    input_dict = {
+        "prompt": "banana",
+        "config": {"seed": None, "temperature": 0.8},
+        "metadata": {"user": "test", "session": None},
+    }
+    result = await async_encode_json(input_dict, async_client)  # type: ignore[arg-type]
+    assert result == {
+        "prompt": "banana",
+        "config": {"temperature": 0.8},
+        "metadata": {"user": "test"},
+    }
+
+
+def test_encode_json_preserves_false_and_zero(client: Replicate):
+    """Test that False and 0 are not filtered out."""
+    input_dict = {
+        "prompt": "banana",
+        "seed": 0,
+        "enable_feature": False,
+        "iterations": None,
+    }
+    result = encode_json(input_dict, client)
+    assert result == {
+        "prompt": "banana",
+        "seed": 0,
+        "enable_feature": False,
+    }
+    assert "iterations" not in result