JSON to TypeScript

Generate TypeScript interfaces, types, or Zod schemas from JSON. Handles nested objects, optional keys, and union types.

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JSON

{
  "id": 42,
  "name": "Ada",
  "email": "ada@example.com",
  "isAdmin": false,
  "tags": ["math", "code"],
  "address": { "city": "London", "postcode": null },
  "orders": [
    { "id": 1, "total": 9.99, "items": [{ "sku": "A1", "qty": 2 }] },
    { "id": 2, "total": 25, "coupon": "SAVE5", "items": [] }
  ]
}

TypeScript

Root type name

Declare as

export readonly properties Mark keys missing from some array items as optional

How to use JSON to TypeScript

Generate TypeScript interfaces from a JSON sample. Paste an API response and get ready-to-use types.

Nested objects become their own named interfaces
Arrays of objects are merged, so keys missing from some items become optional
Mixed values become union types, such as string | null
Output as interface, type, or a Zod schema with an inferred type

JSON to TypeScript FAQs

Is JSON to TypeScript free?

JSON to TypeScript is a free online tool on ReallyUseful.Tools. No account is required.

Does JSON to TypeScript run in my browser?

JSON to TypeScript is designed to run in your browser where supported, so files can stay on your device instead of being uploaded to a server.

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