JSON to TypeScript

Convert JSON to TypeScript interfaces instantly. Free online tool to generate strongly-typed TypeScript types from JSON data. Perfect for API responses and type definitions. No signup required.

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Our JSON to TypeScript Converter instantly transforms JSON data into strongly-typed TypeScript interfaces. This tool is essential for TypeScript developers who need to quickly create type definitions from API responses, configuration files, or any JSON data. The converter automatically handles nested objects, arrays, and infers the correct TypeScript types including string, number, boolean, and complex object types. Perfect for improving type safety in your TypeScript projects.
  1. Paste your JSON data or click Load Demo to try with sample data
  2. The TypeScript interface is generated instantly as you type
  3. Review the generated interface with proper type annotations
  4. Copy the generated code or download as a .ts file
  5. Use the interface in your TypeScript project for type safety

What is a TypeScript interface?

A TypeScript interface defines the structure of an object, specifying what properties it should have and their types. Interfaces help catch errors at compile time and provide better IDE support with autocomplete and type checking.

How does the tool handle nested JSON objects?

The converter creates separate interface definitions for each nested object. For example, if your JSON has a user with an address, it generates both User and Address interfaces with proper type references.

Does it support arrays of objects?

Yes! Arrays of objects are converted to typed arrays like User[] in TypeScript. The tool analyzes the first array item to determine the structure and generates the appropriate interface.

How are null values handled?

Null values in JSON are converted to the 'null' type in TypeScript. You can easily modify the generated code to use union types like 'string | null' if needed.

Can I use this for API response typing?

Absolutely! This is one of the most common use cases. Simply paste a sample API response and get instant TypeScript interfaces to use in your frontend code for type-safe API calls.

What's the difference between interface and type in TypeScript?

Both can define object shapes, but interfaces are more extensible (can be merged and extended). This tool generates interfaces by default, which is the recommended approach for object type definitions.