What does JSON → TypeScript actually do?

JSON to TypeScript builds interfaces from one sample. A value’s type is whatever that sample shows: a number stays number, null often becomes null or an optional, and a field missing from the sample will be missing from the type. It does not union every variant you might see in production.

Does conversion upload my JSON?

No. Type generation runs in your browser.

Are nested objects supported?

Yes — nested objects can be emitted as separate types for cleaner interfaces.

Yes — free JSON to TypeScript conversion with no account.

JSON → TypeScript

Generate TypeScript interfaces from JSON objects. Nested objects become separate types. Free online — runs locally, no upload.

Root name

interfaceexportoptional nulls

JSON Input

TypeScript Output

Nested objects become their own interfaces, named after the property key (PascalCased). Arrays use the first element's type. Property names that aren't valid identifiers are auto-quoted.

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JSON → TypeScript