JSON to Code
Generate type definitions and data models from JSON for multiple programming languages
How to Use JSON to Code Converter
This tool converts JSON data into strongly-typed code structures for various programming languages. It analyzes JSON structure and generates corresponding type definitions, interfaces, or classes that you can use directly in your projects.
Steps to Use
- Paste your JSON data in the left input area, or click "Sample" to load example data
- Select your target programming language from the dropdown menu
- Enter a custom root class name (default is "Root")
- Click "Generate" or the code will auto-generate as you type
- Copy the generated code using the "Copy" button
Key Features
- Multi-language Support: Generate code for TypeScript, C#, Java, Go, Python, Swift, Kotlin, Rust, Dart, and PHP
- Smart Type Inference: Automatically detects data types including strings, numbers, booleans, arrays, and nested objects
- Nested Object Handling: Generates separate class definitions for nested JSON objects
- Array Type Detection: Analyzes array contents to determine the correct element type
- Nullable Field Support: Identifies nullable fields and marks them appropriately in the generated code
- Browser-based Processing: All conversion happens locally in your browser, ensuring data privacy
Type Mapping Reference
The following table shows how JSON data types are converted to each programming language:
| JSON Type | TypeScript | C# | Java | Go | Python |
|---|---|---|---|---|---|
| string | string | string | String | string | str |
| number (int) | number | int | int | int | int |
| number (float) | number | double | double | float64 | float |
| boolean | boolean | bool | boolean | bool | bool |
| null | null | null | null | nil | None |
| array | T[] | List<T> | List<T> | []T | List[T] |
| object | interface | class | class | struct | @dataclass |
Common Use Cases
API Development
When working with REST APIs, convert the JSON response structure into typed models. This enables type checking, autocompletion, and catches potential errors at compile time rather than runtime.
Data Transfer Objects
Generate DTOs (Data Transfer Objects) from JSON schemas for use in backend services. The generated classes can be used directly with JSON serialization libraries like Jackson (Java), Newtonsoft.Json (C#), or encoding/json (Go).
Configuration Files
Convert JSON configuration files into typed configuration classes. This provides IDE support when accessing configuration values and validates the structure at compile time.
Database Models
Transform JSON documents from NoSQL databases into typed models. Useful when working with MongoDB, Firebase, or other document-based databases.
Tips for Best Results
- Use representative JSON data with all possible fields to generate complete type definitions
- Include null values for optional fields to ensure nullable types are detected correctly
- For arrays, include at least one element so the tool can infer the element type
- Use meaningful property names in your JSON as they will become field names in the generated code
- Review the generated code and adjust field modifiers or annotations based on your framework requirements
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