Input

A JSON object or array sample. Use real API response data with complete fields so the tool can accurately infer optional fields and union types. Supports nested objects, arrays of objects, arrays of primitive types, and mixed-type arrays. The more complete the sample data, the more accurate the generated type declarations.

Output

Formatted TypeScript interface declarations, automatically split into multiple independent interfaces by nesting level, linked through type references. The tool infers primitive types such as string, number, boolean, null, and any, auto-generates element types for arrays, and creates child interfaces for nested objects, using Root as the top-level entry point.

How it works

The tool first validates that the JSON is valid, then infers TypeScript types from field values. Objects generate nested interfaces, arrays infer element types, and mixed values preserve union relationships where possible. The more complete the sample, the closer the generated result is to the real API structure.

Supported modes

• Object type inference
• Array type inference
• Auto-split nested interfaces
• Optional field detection
• One-click copy TypeScript

JSON to TypeScript interface example

{
  "id": 1,
  "name": "ToolOrbit",
  "features": ["JSON", "Base64", "UUID"],
  "author": {
    "name": "Developer",
    "active": true
  },
  "tags": [1, 2, 3]
}

interface Root {
  id: number;
  name: string;
  features: string[];
  author: Author;
  tags: number[];
}

interface Author {
  name: string;
  active: boolean;
}