JSON to TypeScript — Generate Interfaces from JSON [2026]
Paste JSON → get TypeScript interfaces instantly. Handles nested objects, arrays, optional fields, and union types. Perfect for typing API responses. 100% browser-based.
What is JSON to TypeScript?
How to Use JSON to TypeScript
Paste your JSON data into the input area. The tool analyzes the structure and generates TypeScript interfaces on the right. Nested objects become separate named interfaces. Arrays infer their element types. Copy the output and paste it into your TypeScript project. Customize the root interface name if needed.
How JSON to TypeScript Works
Common Use Cases
- Typing API response data in React/Next.js applications
- Generating interfaces from database query results
- Creating type definitions for JSON configuration files
- Bootstrapping TypeScript types for a new project from sample data
- Documenting data structures with TypeScript interfaces
Frequently Asked Questions
Does it handle nested objects?▼
Yes. Each nested object generates a separate TypeScript interface with a descriptive name based on the parent key. For example, a "config" key containing an object becomes an interface named Config.
How does it handle arrays?▼
Arrays of primitives generate the appropriate type (e.g., string[]). Arrays of objects generate a named interface for the element type. Mixed arrays generate union types.
Does it support optional fields?▼
If you provide multiple JSON objects in an array and some objects are missing a key that others have, the tool marks that property as optional (with ?).
Is my data safe?▼
Yes. All processing happens in your browser. No data is sent to any server.