Free JSON to TypeScript Converter

Convert a JSON payload into TypeScript interfaces · nested objects and arrays included · ready to paste into your codebase.

Frequently asked

How are arrays with mixed types handled?

Element types are unioned · an array of strings and numbers becomes (string | number)[]. Objects across array elements are merged, and keys missing from some elements are marked optional.

Why type API responses at all?

Untyped responses are where runtime bugs hide: a renamed field fails silently until production. Generated interfaces give the compiler a chance to catch drift · pair them with runtime validation (like zod) for full safety.

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