diff --git a/src/testdatagen/formatters/json_formatter.py b/src/testdatagen/formatters/json_formatter.py
new file mode 100644
index 0000000..bbaf88d
--- /dev/null
+++ b/src/testdatagen/formatters/json_formatter.py
@@ -0,0 +1,57 @@
+"""JSON output formatter."""
+
+import json
+from typing import Any, Dict, List, Optional
+
+
+class JSONFormatter:
+    """Formatter that outputs data in JSON format."""
+
+    def __init__(self, indent: Optional[int] = None, ensure_ascii: bool = False):
+        """Initialize the JSON formatter.
+
+        Args:
+            indent: Number of spaces for indentation (None for no indentation)
+            ensure_ascii: Whether to escape non-ASCII characters
+        """
+        self.indent = indent
+        self.ensure_ascii = ensure_ascii
+
+    def format(self, records: List[Dict[str, Any]]) -> str:
+        """Format records as JSON string.
+
+        Args:
+            records: List of data records to format
+
+        Returns:
+            JSON-formatted string
+        """
+        if len(records) == 1:
+            return json.dumps(
+                records[0],
+                indent=self.indent,
+                ensure_ascii=self.ensure_ascii,
+                default=self._json_serializer
+            )
+
+        return json.dumps(
+            records,
+            indent=self.indent,
+            ensure_ascii=self.ensure_ascii,
+            default=self._json_serializer
+        )
+
+    def _json_serializer(self, obj: Any) -> Any:
+        """Custom JSON serializer for objects not serializable by default.
+
+        Args:
+            obj: Object to serialize
+
+        Returns:
+            Serialized representation
+        """
+        if hasattr(obj, '__dict__'):
+            return obj.__dict__
+        if hasattr(obj, 'isoformat'):
+            return obj.isoformat()
+        return str(obj)
\ No newline at end of file