JSON code generation / TypeScript

Free online JSON to TypeScript interface generator

Generate interfaces for a response with nested records and nullable metadata. Open your JSON locally, then inspect and download the generated files.

Privacy-first processing: pasted or opened JSON stays in this browser tab and is not uploaded to our servers.

Target: TypeScriptChoose serializer and model options in the workbench

Paste formatOpen JSON file

Paste JSON or Drag and Drop your file.

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Try the paginated api response example

The editor starts empty. Load this example only if you want a small source to test the generated model.

Static example with expected output

Verified with the local schema-codegen engine.

API response JSON

{
  "page": 2,
  "nextCursor": null,
  "results": [
    {
      "id": "p-18",
      "title": "Field notes",
      "tags": [
        "api",
        "json"
      ]
    }
  ]
}

Operation

Generate TypeScript interfaces from the sample response.

Language: TypeScript
Serializer: none
Style: interface
File layout: split files

Expected output excerpt (GeneratedRoot.ts)

export interface GeneratedRoot {
  nextCursor: unknown | null;
  page: number;
  results: GeneratedRootResultsItem[];
}

Caveat: The generated interface is compile-time only; add runtime validation separately when accepting untrusted JSON.

Before using this output

Interfaces disappear at runtime. They do not validate fetched JSON or prove that one-sample fields are always present.

Generation analyzes the source shape; it does not validate every future input. Review the language, serializer, enum, primitive, and file-layout options before downloading.

Read the TypeScript workflow

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