diff --git a/datasette/views/row.py b/datasette/views/row.py
index 077c33c2..718ee00c 100644
--- a/datasette/views/row.py
+++ b/datasette/views/row.py
@@ -140,9 +140,6 @@ class RowView(DataView):
                             break
                     if plugin_display_value:
                         rendered_row[column] = str(plugin_display_value)
-                    else:
-                        # Default: convert value to string
-                        rendered_row[column] = "" if value is None else str(value)
                 rendered_rows.append(rendered_row)
             data["render_cell"] = rendered_rows
 
diff --git a/datasette/views/table.py b/datasette/views/table.py
index 9a3ae69f..b07b62ae 100644
--- a/datasette/views/table.py
+++ b/datasette/views/table.py
@@ -1516,9 +1516,6 @@ async def table_view_data(
                         break
                 if plugin_display_value:
                     rendered_row[column] = str(plugin_display_value)
-                else:
-                    # Default: convert value to string
-                    rendered_row[column] = "" if value is None else str(value)
             rendered_rows.append(rendered_row)
         return rendered_rows
 
diff --git a/tests/test_api.py b/tests/test_api.py
index 1571fd5d..41bad84e 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -792,14 +792,15 @@ async def test_row_extra_render_cell():
         assert "rows" in data
 
         # render_cell should be a list with one row (since this is a row page)
+        # Only columns modified by plugins are included (sparse output)
         render_cell = data["render_cell"]
         assert len(render_cell) == 1
 
         # The row: id=1, name='Alice'
         # The 'name' column should be rendered by our plugin as <strong>Alice</strong>
         assert render_cell[0]["name"] == "<strong>Alice</strong>"
-        # The 'id' column should use default rendering (just the value as string)
-        assert render_cell[0]["id"] == "1"
+        # The 'id' column is not included since no plugin modified it
+        assert "id" not in render_cell[0]
 
         # The regular rows should still contain raw values
         assert data["rows"] == [{"id": 1, "name": "Alice"}]
diff --git a/tests/test_table_api.py b/tests/test_table_api.py
index 25419bb8..527550fb 100644
--- a/tests/test_table_api.py
+++ b/tests/test_table_api.py
@@ -1426,18 +1426,19 @@ async def test_extra_render_cell():
         assert "rows" in data
 
         # render_cell should be a list of rows, each row being a dict of column -> rendered HTML
+        # Only columns modified by plugins are included (sparse output)
         render_cell = data["render_cell"]
         assert len(render_cell) == 2
 
         # First row: id=1, name='Alice'
         # The 'name' column should be rendered by our plugin as <strong>Alice</strong>
         assert render_cell[0]["name"] == "<strong>Alice</strong>"
-        # The 'id' column should use default rendering (just the value as string)
-        assert render_cell[0]["id"] == "1"
+        # The 'id' column is not included since no plugin modified it
+        assert "id" not in render_cell[0]
 
         # Second row: id=2, name='Bob'
         assert render_cell[1]["name"] == "<strong>Bob</strong>"
-        assert render_cell[1]["id"] == "2"
+        assert "id" not in render_cell[1]
 
         # The regular rows should still contain raw values
         assert data["rows"] == [