Paste a JSON sample and this tool infers matching TypeScript interfaces for it, including nested objects and arrays. It turns an example API response into ready-to-use types in seconds, entirely in your browser.
How to use it
- Paste a representative JSON object.
- TypeScript interfaces are generated instantly.
- Rename the root interface if you like.
- Copy the types into your project.
About JSON to TypeScript
When you consume an API in TypeScript, you want types that match its responses — but writing them by hand from a sample is tedious and error-prone. This tool parses a JSON example and infers the structure: primitive types for values, nested interfaces for objects, and element types for arrays. The result is a clean set of interfaces you can drop into your codebase and refine. Because it runs locally, you can generate types from a real response without sending it anywhere. Remember that types are inferred from one sample, so optional or nullable fields may need a manual touch.
FAQ
Does it handle nested objects?
Yes. Nested objects become their own interfaces, and arrays are typed by their element type.
Will it detect optional fields?
Types are inferred from the single sample you provide, so fields that are sometimes missing should be marked optional manually.
Is my JSON uploaded?
No. Everything is parsed and generated in your browser.