Schemato

JSON in, types out.

Paste a JSON payload, get TypeScript interfaces inferred instantly — including nullability, arrays, and nested shapes. Saves the five-minute typing tax on every new API integration.

Root type name

JSON input

TypeScript output

export interface User {
  id: string;
  email: string;
  isAdmin: boolean;
  createdAt: string;
  preferences: Preferences;
  projects: Project[];
}

export interface Preferences {
  theme: string;
  newsletter: null;
}

export interface Project {
  id: string;
  name: string;
  starred: boolean;
}

Smart inference

Mixed arrays become unions. Missing fields across array items become optional. Empty arrays become unknown[] — no silent any.

Nested types

Each nested object becomes its own named interface, so the output reads like something you'd write by hand — copy-paste, ship.

Privacy by design

Everything runs in your browser. Paste a payload from a production API — it never crosses the wire.