Is generated TypeScript production-ready?

It is a starting point inferred from sample JSON. Review optional fields, domain constraints, nullability, and naming before production use.

Does it support arrays of objects?

Yes. Arrays of objects are merged into one root interface with optional fields when a key is missing from some items.

No. Type inference runs locally in browser memory.

JSON to TypeScript Interface Generator

Infer TypeScript interfaces from representative JSON payloads for API clients, fixtures, and documentation.

Browser-local

JSON sample

Root interface name

[
  {
    "id": 1,
    "name": "Ada",
    "roles": [
      "admin"
    ],
    "profile": {
      "active": true
    }
  },
  {
    "id": 2,
    "name": "Grace",
    "roles": [
      "qa"
    ],
    "profile": {
      "active": false,
      "score": 9.5
    }
  }
]

264 charactersInference only

TypeScript output

export interface ApiPayloadProfile {
  active: boolean;
  score?: number;
}

export interface ApiPayload {
  id: number;
  name: string;
  roles: string[];
  profile: ApiPayloadProfile;
}

Generated from sample data · review before production

How JSON to TypeScript works

Paste a JSON object or array and choose a root interface name. PayloadHarbor detects primitive values, arrays, nested objects, optional fields across array samples, and property names that need quoted TypeScript syntax.

Developer use cases

Generate quick interfaces for API responses, webhook examples, mock data, OpenAPI notes, and frontend model prototypes without sending sample payloads to a backend.

Review before production

Inference cannot know server-side rules, enums, branded IDs, dates, nullable intent, or undocumented fields. Treat the output as scaffolding, not an authoritative contract.

TypeScript generation questions

Is generated TypeScript production-ready?: It is a starting point inferred from sample JSON. Review optional fields, domain constraints, nullability, and naming before production use.
Does it support arrays of objects?: Yes. Arrays of objects are merged into one root interface with optional fields when a key is missing from some items.
Is JSON uploaded?: No. Type inference runs locally in browser memory.

What this JSON to TypeScript does

Use this JSON to TypeScript interface generator to infer TypeScript types from representative JSON payload samples. It is designed for API clients, frontend mocks, fixture files, and documentation drafts where a quick strongly typed starting point helps development.

When developers use it

Generate TypeScript interfaces from API responses, webhook payloads, and mock JSON files.
Infer nested object and array types before moving data into a typed frontend model.
Create copy-ready interface scaffolding for tests, SDK notes, and code reviews.

Privacy, input, and output

Type inference runs in the browser session. PayloadHarbor does not upload the JSON sample or generated TypeScript output.

Paste a JSON object or array, choose a root interface name, and generate TypeScript. Arrays of objects are merged into one interface and keys missing from some samples become optional properties.

Validation rules and limitations

Generated interfaces are inferred from observed values only; they cannot know server-side enums, branded types, required-but-missing fields, or business constraints.
Review nullability, date strings, identifier types, and optional fields before using generated types in production code.