JSON to Dart Converter - Advance Dart Model Generation

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Our JSON to Dart Converter allows you to instantly transform any JSON object or array into fully structured Dart classes, ready to integrate into your Flutter or Dart projects. It supports advanced features like null safety, private fields, required fields, default values, and nested class generation. Everything runs entirely in the browser, ensuring fast, secure, and offline conversion.

How the JSON to Dart Tool Works

This converter analyzes the JSON structure and automatically generates Dart classes for each object and nested object or array. Key steps include:

  • Parsing JSON: The tool validates and parses your JSON string. Invalid JSON is flagged in real-time with error messages.
  • Generating Classes: Each object becomes a Dart class, with nested objects or arrays generating additional nested classes.
  • Field Handling: Options such as null safety, private fields, required fields, and default values are applied to each field.
  • Constructor & Serialization: For every class, a Dart constructor, fromJson, and toJson method is generated, ensuring the classes can be immediately used for JSON deserialization and serialization.
  • Live Preview: As you type or upload JSON, the Dart code updates instantly in the preview pane.

Tool Features in Detail

  • Null Safety: If enabled, fields with nullable values in JSON are appended with ? in Dart (e.g., String? name;).
  • Private Fields: Prefix fields with an underscore to restrict direct access outside the class.
  • Required Fields: Mark fields as required in the constructor to prevent runtime null errors.
  • Default Values: Primitive fields can be initialized with default values inferred from JSON.
  • Nested Arrays & Objects: The tool intelligently creates nested classes for arrays of objects, handling multiple levels of hierarchy.
  • List of Primitives: Arrays containing primitives like numbers, strings, or booleans are handled with proper Dart List typing.
  • Sanitized Field Names: JSON keys with spaces, special characters, or numeric prefixes are sanitized to valid Dart identifiers.
  • Live Validation: Invalid JSON triggers inline error messages without crashing the tool.
  • Copy / Download: Easily copy the generated Dart code or download it as model.dart.

Simple JSON Conversion Example

Input JSON

{
  "id": 1,
  "name": "Alice",
  "isActive": true
}

Output Dart

class Root {
  int id;
  String name;
  bool isActive;

  Root({
    required this.id,
    required this.name,
    required this.isActive,
  });

  factory Root.fromJson(Map<String, dynamic> json) => Root(
    id: json['id'] as int,
    name: json['name'] as String,
    isActive: json['isActive'] as bool,
  );

  Map<String, dynamic> toJson() => {
    'id': id,
    'name': name,
    'isActive': isActive,
  };
}

Supported Use Cases

  • Generate Dart models from API responses for Flutter apps
  • Quickly prototype complex nested JSON structures
  • Automatically handle arrays of objects and nested objects
  • Enforce null safety, required fields, or private fields for production-ready code
  • Generate POJO-like classes with full fromJson and toJson methods

Why Our JSON to Dart Converter Stands Out

This converter is designed to minimize developer errors, handle deeply nested JSON objects, and provide multiple options that are fully compliant with modern Dart & Flutter best practices. Unlike basic online converters, it supports:

  • Arrays of nested objects with correct Dart typing
  • Sanitization of field names to valid Dart identifiers
  • Optional features like null safety, private fields, required fields, default values
  • Instant live preview with syntax-highlighted, ready-to-use Dart code

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