JSON to TypeScript

Generate strongly-typed TypeScript interfaces (`interface RootObject { ... }`) and type aliases from JSON sample data. Recursively infers nested object structures, array element types, optional properties, primitive types, and null values.

Why Use This Tool?

• TypeScript Frontend Development: Quickly generate TypeScript interfaces for API response data in React, Vue, or Angular apps.
• Type Safety: Eliminate manual typing errors when creating TypeScript interfaces for backend API payloads.
• Nested Object Structuring: Automatically extract nested JSON objects into separate sub-interfaces.

How to Use

1. Paste your sample JSON payload into the editor.
2. Set Root Interface Name (e.g. `UserResponse`).
3. Copy the generated TypeScript interface code.

Real Working Example

Input:

JSON: { "id": 1, "name": "John", "roles": ["admin", "user"], "address": { "city": "NYC" } }

Output Result:

TypeScript Code:
export interface Address {
  city: string;
}

export interface UserResponse {
  id: number;
  name: string;
  roles: string[];
  address: Address;
}

Important Technical Details & Specifications

• Recursive Type Inference Engine: Recursively analyzes JSON types (string, number, boolean, null, object, array).
• Array Union Type Merging: Merges heterogeneous array element types into TypeScript union types (e.g. `(string | number)[]`).
• Local Memory Execution: Zero network overhead.

Related Developer Tools

• JSON to Go Struct: Generate typed Go structs from JSON.
• JSON Schema Validator: Validate JSON against schemas.
• JSON Formatter: Prettify and format JSON.