JSON to TypeScript Generator

One sample, one shape

The types describe the sample exactly. A field that was null becomes type null, an empty array becomes any[], and objects inside an array take their shape from the first element only. Edit those by hand: null usually means string | null or similar, and fields that only some records carry should be optional. Two nested objects with the same key name share one interface, named after the key, so check that its fields fit both.

Types do not check data

TypeScript types disappear when code is compiled. If an API later sends a field as a string instead of a number, nothing stops it at runtime and the error appears somewhere else. For data from outside your code, validate it when it arrives: against a JSON Schema, which you can test in the JSON Schema validator, or with a runtime validation library.

Whether to use interface or type rarely matters for plain data. Interfaces can be extended and merged; type aliases can also express unions.

How to use it

1. Paste your JSON payload into the input box.
2. Configure root interface name, declaration style, or optional fields.
3. Copy the generated TypeScript code.

Privacy & limitations

Your JSON data is parsed entirely in browser RAM. Zero server uploads.