JSON to TypeScript
Generate interfaces from JSON.
Runs entirely in your browser — nothing you enter is uploaded, logged, or tracked.
Turn an example JSON payload into ready-to-use TypeScript interfaces. It walks nested objects and arrays, names them sensibly, and infers optional fields and union types from your data — then you copy the result. Nothing is sent anywhere.
Frequently asked questions
How are the types inferred?
Each object becomes an interface; primitives map to string/number/boolean; arrays are typed by their elements (merging object shapes and forming unions when needed). Missing or null values become optional.
Does it handle nested objects and arrays?
Yes. Nested objects get their own named interfaces, and arrays of objects are merged into a single element interface so the types stay clean.
Is my JSON sent to a server?
No — parsing and generation run entirely in your browser. Your data never leaves the page.