JSON to TypeScript Converter
Paste JSON and instantly generate TypeScript interfaces or type aliases. Supports nested objects, arrays, and union types.
Why Convert JSON to TypeScript?
TypeScript interfaces provide compile-time type safety when working with JSON data from APIs. Instead of manually writing types, paste the JSON response and get accurate TypeScript definitions instantly.
Supported Features
- - Nested objects with separate interfaces
- - Array type inference and union types
- - Customizable root interface name
- - Interface or type alias output
How to Convert JSON to TypeScript Online
- 1. Choose interface or type output mode using the toggle.
- 2. Optionally change the Root name for the generated type (defaults to "Root").
- 3. Paste your JSON data into the left panel. TypeScript output generates instantly.
- 4. Click Copy to copy the generated TypeScript to your clipboard.
Frequently Asked Questions
Does this tool handle nested JSON objects?
Yes. Each nested object is extracted into its own named interface or type alias. The parent type references the child type by name, producing clean and reusable TypeScript definitions.
How are arrays handled?
Homogeneous arrays (all elements the same type) produce clean types like string[]. Mixed-type arrays generate union types like (string | number)[]. Empty arrays default to unknown[].
Can I use the output directly in my project?
Absolutely. The generated TypeScript is valid and can be copied directly into your .ts or .tsx files. All interfaces are exported so you can import them where needed.
Is my JSON data sent to a server?
No. All conversion happens entirely in your browser using JavaScript. Your data is never uploaded, stored, or logged anywhere.