Free Online JSON to TypeScript Converter

What the JSON to TypeScript Converter does

The JSON to TypeScript Converter reads a sample JSON object and generates matching TypeScript interfaces. Each nested object gets its own named interface, and each property gets a type inferred from its value: string, number, boolean, null, an array type, or another interface.

Set the interface name in the Interface name field. If the JSON is an array, the types come from its first element, and a list type such as type UserList = User[]; is added.

When to use it

• Typing the response of an API you call from a TypeScript frontend or Node.js service.
• Starting a data model from a real payload instead of writing interfaces by hand.
• Documenting the shape of a webhook or event payload for your team.

Worked example

Input

{"id": 1, "name": "Ana", "active": true, "address": {"city": "Lisbon"}, "tags": ["admin"]}

Output

interface Address {
  city: string;
}

interface User {
  id: number;
  name: string;
  active: boolean;
  address: Address;
  tags: string[];
}

Common questions about the JSON to TypeScript Converter