JSON to Python Class Generator – Dataclasses

JSON Input

Root class name

Output will appear here

Generate Python dataclasses from a JSON sample

Paste a JSON sample and get typed Python @dataclass definitions, ready to paste into your code. Nested objects become their own dataclasses automatically, with proper type hints throughout.

What the generator produces

Typed fields using Python's type hint syntax (int, float, str, bool, List[T]).
snake_case field names, converted automatically even if your JSON uses camelCase keys.
from __future__ import annotations included automatically whenever a class references another class defined later in the file — without it, Python would raise a NameError on forward references, since dataclass type hints are evaluated at class-definition time by default.
Deduplicated classes for repeated shapes, same as our other class generators.

Typical use cases

Typed API clients: Scaffold dataclasses for a JSON API response before parsing it with dataclasses or a library like Pydantic.
Config objects: Turn a JSON config file into a typed Python structure instead of working with raw dictionaries.

Frequently Asked Questions

Without it, a dataclass that references another class defined later in the same file raises a NameError at class-definition time, since Python evaluates type hints immediately by default. This import defers that evaluation, making forward references safe regardless of class order — we actually hit this exact bug while building the generator and fixed it this way.

Not currently — it generates standard library @dataclass definitions. Converting to Pydantic's BaseModel style is usually a small manual change (swap the decorator and base class) once you have the field types.

Whole numbers become int; numbers with a decimal point become float, matching Python's own type distinction.

No, generation happens entirely in your browser.