JSON → TypeScript

Generate TypeScript interfaces or types from a JSON sample.

Private by design. Your input never leaves this browser. Conversions run locally on your device.

What this tool handles

Emits an interface or a type alias, named from the root type name you choose.
Nested objects become their own named interfaces rather than inline literals.
Unknown and mixed types are written as unknown or any, whichever you select.
Types describe the sample you paste: a field that is never null in the sample is not optional.

{"id":1,"name":"Ada","address":{"city":"London"},"tags":["a","b"]}

export interface Address {
  city: string;
}

export interface Root {
  id: number;
  name: string;
  address: Address;
  tags: string[];
}

JSON → Zod — Generate a Zod schema from a JSON sample.
JSON → Python — Generate Python dataclasses from a JSON sample.
JSON → Go — Generate Go structs with json tags from a JSON sample.
JSON → SQL — Generate a CREATE TABLE statement from flat JSON rows.
JSON → JSON Schema — Infer a JSON Schema from a sample document.
Convert any format — Pick an input format and an output format and convert between any pair.