JSON to TypeScript Interfaces Converter

Convert raw JSON data and REST API payloads into strongly-typed TypeScript interfaces and type aliases with automatic nested object resolution.

Root Name:
Input JSON Payload Valid JSON
Generated TypeScript Interfaces 1 interface generated
Root Interface: ApiResponse
Status: 100% Client-Side TypeScript AST

How to Convert JSON to TypeScript Interfaces Online

Working with REST API endpoints or complex JSON documents in TypeScript requires writing boilerplate type definitions to ensure compile-time type safety. Manually mapping deeply nested objects and arrays can take hours.

Our JSON to TypeScript generator recursively parses your sample JSON payload, detects primitive types (string, number, boolean, null), identifies arrays of objects, and generates clean, modular TypeScript interface or type definitions.

Key Advantages for TypeScript Developers

  • Recursive Type Inference: Automatically detects nested objects and generates separate, well-named TypeScript interfaces.
  • Array & Tuple Resolution: Correctly types arrays of objects as Item[] and scalar arrays as string[] or number[].
  • Readonly Modifiers: Toggle readonly properties for immutable state management in React, Redux, or Zustand.
  • Zero Data Uploads: JSON parsing occurs locally in your browser memory, keeping your API data confidential.

Frequently Asked Questions (FAQ)

What is the difference between interface and type alias in TypeScript?
An interface is ideal for defining object shapes and supports declaration merging. A type alias can represent primitive unions, tuples, and object types. Our tool supports both formats via a simple toggle.
What happens if a field is null in the JSON payload?
When the parser encounters a null value, it assigns the property type as any or null so you can refine it to your specific nullable domain model.