Is the JSON to Dart generator free?

Yes, it is completely free to use. No registration, login, or payment required. All features are available directly in your browser.

Does the generated code support null safety?

Yes. The generated Dart code fully supports Dart 3.x null safety. Optional fields are declared as nullable types (?), required fields use the required keyword. The code also supports final properties, copyWith methods, and JSON serialization/deserialization.

Is my JSON data sent to any server?

No. All JSON parsing and code generation happens entirely in your browser. Your data never leaves your computer. You can safely process JSON containing API keys, personal data, or business-sensitive information. The tool works offline too.

What JSON data types are supported?

All standard JSON types are supported: String, numbers (int/double), booleans, arrays (List), nested objects (custom classes), and null values. The tool intelligently infers the most appropriate Dart type for each field. Nested objects are automatically converted into separate Dart classes with proper relationships.

Can I use json_serializable or freezed annotations?

Yes! The tool supports three code generation modes: plain Dart classes (no dependencies), json_serializable annotations (with @JsonSerializable() and generated .g.dart), and freezed annotations (with @freezed and immutable classes). You can also enable Equatable support and copyWith methods.

Free JSON to Dart - Online Dart Class Generator

❓ Frequently Asked Questions

Is this tool suitable for Flutter developers?▼

Absolutely. This tool is designed specifically for Flutter/Dart developers. Generated code fully supports Dart 3.x null safety, required properties, copyWith methods, and fromJson/toJson serialization. Whether you use plain Dart classes, json_serializable, or freezed, this tool has you covered. It's perfect for quickly creating model classes from API responses.

Is my JSON data secure?▼

Absolutely. All processing happens locally in your browser. No data is uploaded to any server. You can safely process JSON containing API keys, user personal information, or business-sensitive data. The tool works offline as well, giving you complete control over your data.

How are nested JSON objects handled?▼

The tool automatically detects nested objects and arrays, generating separate Dart classes for each nested structure with proper relationships. For example, if your JSON contains an "address" object, the tool creates an Address class and declares it as Address? address in the parent class. The fromJson and toJson methods support deep serialization/deserialization.

What's the difference between plain, json_serializable, and freezed?▼

Plain Dart classes require no dependencies and are self-contained — ideal for small projects. json_serializable uses @JsonKey annotations to auto-generate fromJson/toJson code via build_runner — great for large projects with many models. freezed provides immutability, copyWith, union types, and pattern matching — best for complex state management. This tool supports all three modes.

Can I customize the generated class names?▼

The tool automatically generates class names based on JSON keys using PascalCase convention. For the root object, it uses "RootModel". You can easily rename classes by editing the class declaration line in the generated code. For custom type mappings (e.g., treating a string as DateTime), you may need to adjust the generated code manually. Custom type mapping configuration is planned for a future release.

🔧 JSON to Dart Class Generator

❓ Frequently Asked Questions