PTPureToolkit
Code generationLocal-only

JSON to TypeScript Interface Generator

Paste JSON examples and generate TypeScript interfaces or type aliases with nested types, readonly options, optional nullable fields, and warnings for mixed arrays or invalid identifiers.

This tool runs locally in your browser. Your input is not uploaded.

No uploadsNo server logsNo runtime APIsBrowser-only transforms
Options

Generated TypeScript output

Generate TypeScript to see interface output.

Examples

API user

Generate a root interface and nested profile interface.

{
  "id": 1,
  "name": "Ada",
  "email": null,
  "profile": {
    "active": true,
    "score": 9.5
  }
}

Product list

Generate item types from a JSON array example.

[
  {
    "sku": "A-1",
    "price": 12.5,
    "tags": [
      "dev",
      "tool"
    ]
  }
]

How it works

  1. The browser parses JSON and infers TypeScript types from example values.
  2. Nested objects become named interfaces or type aliases.
  3. Mixed arrays and invalid property identifiers generate visible warnings for review.

Limitations

  • Generated types are inferred from examples, not a complete schema contract.
  • Mixed arrays may need manual refinement after generation.
  • Invalid property names are quoted rather than renamed so the output matches JSON shape.

FAQ

Does this tool upload my JSON?

No. JSON parsing and TypeScript generation run locally in your browser.

Can it generate type aliases instead of interfaces?

Yes. Use the declaration style option to switch between interface and type alias output.

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