JSON to Dart Converter

Why convert JSON to Dart by hand

Every Flutter app that talks to an API ends up writing the same boilerplate: a class per response shape, a fromJson factory that reads each key, a toJson that writes it back, and usually a copyWith for state updates. Doing this by hand for a payload with fifteen fields is slow and it's exactly the kind of work where a typo in a key name fails silently at runtime instead of at compile time.

This tool parses the JSON you paste in, infers a Dart type for each field (String, int, double, bool, nested objects, and typed lists), and generates a null-safe class with fromJson, toJson, and copyWith already written. If a value is a nested object, it generates a class for that too.

Freezed and json_serializable output

Pick the output style that matches how your project is already structured. The plain Dart output works with zero dependencies, which is fine for a small app or a quick prototype. If you're already using Freezed or json_serializable for code generation, switch to that output format instead, since mixing manually-written model classes with generated ones in the same project usually causes more confusion than it saves.

What it won't get right

Type inference from a single JSON sample has a real limitation: if a field is null in your sample, there's no way to know its real type, so it falls back to dynamic. Always paste a JSON sample where every field is actually populated, and double-check the output against your API's real response before shipping it.