JSON to TypeScript Converter

Every nested object becomes its own named interface (derived from its key, PascalCased), referenced by the parent — the shape you'd write by hand. Arrays are typed from their elements: uniform arrays get T[], mixed ones get a union like (string | number)[].

One sample can't reveal optionality — a field present in this response might be absent in the next. After generating, mark fields you know vary with ? or | null. For guaranteed-complete types, the API's own OpenAPI schema (if it has one) beats inference from samples.

Here, yes — parsing and generation happen entirely in your browser with nothing transmitted, which matters because real responses carry tokens, emails, and internal IDs. That's precisely the data you shouldn't feed to a converter that processes server-side.

For object shapes they're nearly interchangeable; interfaces get slightly nicer compiler errors and support declaration merging. If your codebase standardizes on type aliases, a find-and-replace of 'interface X {' to 'type X = {' converts the output in seconds.