JSON ↔ TypeScript Converter
Convert JSON to TypeScript interfaces or generate JSON examples from TypeScript definitions.
Conversion Options
Features
Bidirectional Conversion
Convert JSON to TypeScript interfaces or generate JSON examples from TypeScript definitions. Switch between modes as needed.
Nested Type Support
Automatically handles nested objects and arrays, creating separate interfaces for complex structures with proper naming.
Customizable Output
Configure interface names, optional fields, readonly modifiers, export keywords, and more to match your project conventions.
Type Inference
Automatically infers TypeScript types from JSON values including strings, numbers, booleans, null, arrays, and nested objects.
1MB Data Support
Process large JSON files up to 1MB. Optimized algorithms handle complex nested structures without performance issues.
100% Client-Side
All conversion happens in your browser. Your data never leaves your device—complete privacy for sensitive API schemas.
How to Convert JSON to TypeScript
- Select JSON → TypeScript mode using the toggle buttons at the top.
- Paste your JSON data into the input textarea. The tool validates JSON syntax automatically.
- Configure interface options such as the interface name, optional fields, and readonly modifiers.
- Click Convert or press Ctrl+Enter to generate TypeScript interfaces.
- Copy or download the generated TypeScript code for your project.
How to Generate JSON from TypeScript
- Select TypeScript → JSON mode using the toggle buttons at the top.
- Paste your TypeScript interface into the input textarea. The tool validates the syntax.
- Click Convert or press Ctrl+Enter to generate a sample JSON object.
- Review the generated JSON which includes sample values based on the type definitions.
- Copy or download the JSON for testing or documentation purposes.
Why TypeScript Interfaces Matter
TypeScript interfaces provide compile-time type checking that catches errors before they reach production. By defining the shape of your data, you get autocomplete suggestions, refactoring support, and documentation that stays in sync with your code.
When working with APIs, generating TypeScript interfaces from JSON responses ensures your frontend code matches the backend contract. This reduces integration bugs and makes it easier for teams to collaborate across frontend and backend boundaries. Type-safe code also improves developer experience with better IDE support and fewer runtime errors.
Common Developer Use Cases
API Development
Generate TypeScript interfaces from API responses automatically. Ensure type safety when consuming REST or GraphQL endpoints and reduce integration errors between frontend and backend teams.
Frontend Development
Convert backend JSON schemas to TypeScript types for React, Vue, or Angular projects. Get autocomplete, type checking, and inline documentation for your data models.
Testing & Mocking
Generate sample JSON data from TypeScript interfaces for unit tests and mock servers. Create realistic test fixtures that match your type definitions automatically.
Documentation
Document your API responses with TypeScript interfaces. Generate JSON examples for API documentation that stay synchronized with your actual type definitions.
Frequently Asked Questions
How do I generate TypeScript interfaces from JSON?
Paste your JSON data into the input field, select JSON → TypeScript mode, and click Convert. The tool automatically infers types from JSON values and generates clean, properly formatted TypeScript interfaces.
Can TypeScript be converted back to JSON?
Yes! Switch to TypeScript → JSON mode, paste your interface definition, and the tool generates a sample JSON object with placeholder values based on the type definitions.
Why use TypeScript interfaces for API responses?
TypeScript interfaces provide compile-time type checking, autocomplete support, and self-documenting code. They catch type errors before runtime and improve developer experience when working with API data.
Is the conversion done in the browser?
Yes, all conversion happens entirely in your browser using JavaScript. Your data never leaves your device, ensuring complete privacy for sensitive API schemas.