JSON to TypeScript Type Generator

Automated Schema Inference

Stop manually writing data structures. Our type inference engine analyzes your JSON sample and automatically generates strict type definitions for multiple languages.

TypeScriptGoC#JavaPythonSwift

* All code generation occurs in your browser memory. We never store or transmit your schemas, ensuring total privacy for your proprietary data structures.

Generate TypeScript types from representative JSON

Paste a representative JSON value to infer nested TypeScript declarations. Review the result before using it as an API contract: inference can describe only the values present in the sample.

Example input

{"id":7,"name":"Ada","tags":["admin"],"profile":null}

Expected output

type Root = {
  id: number;
  name: string;
  tags: string[];
  profile: null;
};

Behavior

Infers primitives, objects, arrays, and nested structures.
Repeated array members are used to infer a compatible element shape.
Generated declarations can be copied and refined in your editor.

Limits and edge cases

A missing property cannot be inferred as optional from one sample.
Dates and UUIDs arrive as strings unless you refine them manually.
Mixed or empty arrays may require explicit union or element types.

Processing note: tool input stays in the browser. Readme.now analytics records page usage, not the payload you paste or the generated output.

Authoritative reference: TypeScript object types

JSON to TypeScript Types