diff --git a/src/python-fastui/fastui/json_schema.py b/src/python-fastui/fastui/json_schema.py
index 49492796..c1de21f6 100644
--- a/src/python-fastui/fastui/json_schema.py
+++ b/src/python-fastui/fastui/json_schema.py
@@ -185,6 +185,7 @@ def json_schema_field_to_field(
             initial=schema.get('default'),
             description=schema.get('description'),
             mode=schema.get('mode', 'checkbox'),
+            class_name=schema.get('className'),
         )
     elif field := special_string_field(schema, name, title, required, False):
         return field
@@ -192,11 +193,13 @@ def json_schema_field_to_field(
         return FormFieldInput(
             name=name,
             title=title,
+            placeholder=schema.get('placeholder'),
             html_type=input_html_type(schema),
             required=required,
             initial=schema.get('default'),
             autocomplete=schema.get('autocomplete'),
             description=schema.get('description'),
+            class_name=schema.get('className'),
         )
 
 
@@ -246,6 +249,7 @@ def special_string_field(
                 multiple=multiple,
                 accept=schema.get('accept'),
                 description=schema.get('description'),
+                class_name=schema.get('className'),
             )
         elif schema.get('format') == 'textarea':
             return FormFieldTextarea(
@@ -270,6 +274,7 @@ def special_string_field(
                 options=[SelectOption(value=v, label=enum_labels.get(v) or as_title(v)) for v in enum],
                 initial=schema.get('default'),
                 description=schema.get('description'),
+                class_name=schema.get('className'),
                 autocomplete=schema.get('autocomplete'),
             )
         elif search_url := schema.get('search_url'):
@@ -282,6 +287,7 @@ def special_string_field(
                 multiple=multiple,
                 initial=schema.get('initial'),
                 description=schema.get('description'),
+                class_name=schema.get('className'),
             )
 
 
diff --git a/src/python-fastui/tests/test_forms.py b/src/python-fastui/tests/test_forms.py
index b0919fad..c0f1b528 100644
--- a/src/python-fastui/tests/test_forms.py
+++ b/src/python-fastui/tests/test_forms.py
@@ -6,7 +6,7 @@
 from fastapi import HTTPException
 from fastui import components
 from fastui.forms import FormFile, Textarea, fastui_form
-from pydantic import BaseModel
+from pydantic import BaseModel, Field
 from starlette.datastructures import FormData, Headers, UploadFile
 from typing_extensions import Annotated
 
@@ -469,3 +469,99 @@ def test_form_textarea_form_fields():
             }
         ],
     }
+
+
+class FormWithCustomClassNameField(BaseModel):
+    name: str
+    size: int = 4
+    internal_id: int = Field(
+        title='Internal id',
+        json_schema_extra={
+            'className': 'visually-hidden',
+        },
+    )
+
+
+def test_fields_with_custom_class_name():
+    m = components.ModelForm(model=FormWithCustomClassNameField, submit_url='/foobar/')
+
+    assert m.model_dump(by_alias=True, exclude_none=True) == {
+        'submitUrl': '/foobar/',
+        'method': 'POST',
+        'type': 'ModelForm',
+        'formFields': [
+            {
+                'name': 'name',
+                'title': ['Name'],
+                'required': True,
+                'locked': False,
+                'htmlType': 'text',
+                'type': 'FormFieldInput',
+            },
+            {
+                'name': 'size',
+                'title': ['Size'],
+                'initial': 4,
+                'required': False,
+                'locked': False,
+                'htmlType': 'number',
+                'type': 'FormFieldInput',
+            },
+            {
+                'className': 'visually-hidden',
+                'htmlType': 'number',
+                'locked': False,
+                'name': 'internal_id',
+                'required': True,
+                'title': ['Internal id'],
+                'type': 'FormFieldInput',
+            },
+        ],
+    }
+
+
+class FormWithPlaceholderField(BaseModel):
+    name: str
+    size: int = 4
+    internal_id: int = Field(
+        title='Internal id',
+        json_schema_extra={'placeholder': '1234'},
+    )
+
+
+def test_fields_with_placeholder_values():
+    m = components.ModelForm(model=FormWithPlaceholderField, submit_url='/foobar/')
+
+    assert m.model_dump(by_alias=True, exclude_none=True) == {
+        'submitUrl': '/foobar/',
+        'method': 'POST',
+        'type': 'ModelForm',
+        'formFields': [
+            {
+                'name': 'name',
+                'title': ['Name'],
+                'required': True,
+                'locked': False,
+                'htmlType': 'text',
+                'type': 'FormFieldInput',
+            },
+            {
+                'name': 'size',
+                'title': ['Size'],
+                'initial': 4,
+                'required': False,
+                'locked': False,
+                'htmlType': 'number',
+                'type': 'FormFieldInput',
+            },
+            {
+                'htmlType': 'number',
+                'locked': False,
+                'name': 'internal_id',
+                'placeholder': '1234',
+                'required': True,
+                'title': ['Internal id'],
+                'type': 'FormFieldInput',
+            },
+        ],
+    }