DevTools

JSON → Dart Models

Generate Dart model classes from JSON. Supports nested models, null safety, and fromJson/toJson.

JSON Input

Generated Dart Code

Paste JSON to generate Dart models

JSON to Dart Model Generator

Paste any JSON object and get ready-to-use Dart model classes for Flutter apps. Toggle null safety, fromJson/toJson factories, and set your root class name. Nested objects are automatically extracted into separate named classes.

Frequently Asked Questions

Does this generate null-safe Dart code?
Yes. With null safety enabled, the generator adds ? nullable type annotations for fields that could be null. It follows Dart 2.12+ null safety conventions.
What does fromJson/toJson do?
fromJson is a factory constructor that creates a model instance from a Map<String, dynamic>. toJson returns the model as a Map for JSON serialization. Both are required for most REST API workflows in Flutter/Dart.
Does it handle nested objects?
Yes. Nested JSON objects generate separate named Dart classes. The parent class references child classes by name.
Is my JSON sent to a server?
No. All code generation runs entirely in JavaScript in your browser. Your JSON data never leaves your device.