JSON to TypeScript Interface Generator

Convert any JSON data into clean TypeScript interfaces instantly. This tool analyzes your JSON structure and generates accurate TypeScript types including nested objects, arrays, numbers, strings, booleans, and null values.

All processing runs directly in your browser using WebAssembly, so your data never leaves your device.

Features List

In-browser conversion (no server upload)
Supports nested objects and arrays
Detects number, string, boolean, null
Generates clean interface names
Copy & download types.ts
Works offline after load

How to Use

Paste your JSON in the input box
Click Generate TS
Copy the produced interface
Use it in your TypeScript project

Example

JSON Input

JSON

{
  "id": 1,
  "title": "demo",
  "price": 99,
  "tags": ["js","ts"]
}

Generated Output TypeScript

interface Root {
  id: number;
  title: string;
  price: number;
  tags: string[];
}

Example 2 - Nested

JSON

{
  "user": {
    "name": "Ali",
    "age": 25
  },
  "active": true
}

TypeScript

interface User {
  name: string;
  age: number;
}
interface Root {
  user: User;
  active: boolean;
}

Convert JSON to TypeScript Interface

Paste your JSON data into the input box and click Convert to generate accurate TypeScript interfaces instantly. The tool analyzes objects, arrays, and nested structures and creates ready-to-use types. Copy the result or download it as a .ts file for use in your project.

JSON input

Type Name:

Output Format:

TypeScript (interface)TypeScript (type alias)

TypeScript Interface

What is a TypeScript Interface?

A TypeScript interface is a blueprint that describes the shape of a JavaScript object. It defines what properties an object should have and what type each property must be. Interfaces do not produce real JavaScript code they exist only during development to provide type safety, autocomplete, and error checking.

Using interfaces helps developers work with API responses confidently. When JSON data is converted into a TypeScript interface, your editor knows exactly which fields exist and prevents mistakes such as using the wrong property name or assigning the wrong data type.

FAQ

What does this tool do?

It analyzes your JSON structure and automatically generates matching TypeScript interfaces or type aliases. Nested objects, arrays, booleans, numbers, strings, and null values are detected and converted correctly.

Is my JSON sent to a server?

No. The conversion runs completely in your browser using WebAssembly. Your data never leaves your device.

What types are supported?

The generator supports:

string, number, boolean
arrays and nested arrays
objects and nested objects
null values
mixed structures

Interface vs Type alias - which should I choose?

Both work the same for most cases.

Use interface when you want to extend or merge types later.

Use type alias when you need unions or more complex type expressions.

Can I use the result in React or Node projects?

Yes. Simply copy the generated code into a .ts file and import it anywhere in your TypeScript, React, Next.js, Angular, or Node project.

What if my JSON is invalid?

The tool will show an error message and will not generate TypeScript until the JSON syntax is correct.

Does it support large JSON files?

Yes. The WebAssembly engine is fast and works with large structures, but very huge files may depend on your browser memory limits.

Can I download the result?

Yes. Use the Download .ts button to save the generated interface as a TypeScript file.

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