JSON to TypeScript Interface Generator
Paste a JSON object and instantly generate TypeScript interfaces with proper type inference for nested structures and arrays.
interface User {
id: number;
name: string;
email: string;
roles: string[];
active: boolean;
score: number;
address: null;
}
interface Root {
user: User;
}✅ Generates interface declarations from a JSON object.
✅ Supports nested objects, arrays, booleans, numbers, strings and null.
✅ All processing happens in your browser — no data is sent anywhere.
Frequently Asked Questions
What does JSON to TypeScript do?
It converts a JSON object into TypeScript interface declarations, inferring types automatically so you can use them in your TypeScript projects.
Does it support nested objects?
Yes. Each nested object generates its own interface, which is referenced from the parent interface.
Is my JSON data sent to a server?
No. The conversion runs entirely in your browser using JavaScript — your data never leaves your device.
Does it handle arrays?
Yes. Arrays infer the type of the first element and produce a typed array (e.g. string[], number[], or a custom interface[]).