Free JSON to TypeScript Converter

How to Generate TypeScript from JSON

Paste your JSON into the left panel and TypeScript interfaces appear instantly on the right. The converter analyzes the structure of your JSON — objects become interfaces, arrays are typed with their element types, and primitives are mapped to string, number, or boolean. You can customize the root interface name and copy or download the generated code.

When to Use JSON to TypeScript

Use this tool when consuming REST APIs and you need type-safe interfaces for the response data, when migrating JavaScript projects to TypeScript, or when you want to quickly scaffold types from sample JSON payloads. TypeScript interfaces help catch bugs at compile time and improve editor autocompletion.

Frequently Asked Questions

What does it generate?

It generates TypeScript interfaces that match the shape of your JSON data, with properly typed fields for strings, numbers, booleans, and arrays.

Does it handle nested objects?

Yes — each nested object gets its own separate interface. This keeps the output clean and reusable across your codebase.

Can I customize the root name?

Yes — you can set a custom name for the root interface. Nested interfaces are automatically named based on their property keys.

Does it infer types?

Yes — the converter automatically infers string, number, boolean, and array types from your JSON values. Arrays of objects get their own typed interfaces.

Is this converter free?

Yes — completely free, forever. No sign-up, no account, no usage limits.

Is my data safe?

All conversion happens locally in your browser using JavaScript. Your JSON is never uploaded to any server. It's safe to use with sensitive or proprietary data.