JSON to Python — Generate Pydantic, Dataclass & TypedDict

This JSON to Python converter turns any JSON sample into typed Python classes. Pick your output style — Pydantic for validation and FastAPI, a plain dataclass, or a TypedDict for lightweight type hints — and the tool infers a Python type for every field, generating nested classes for nested objects. It runs entirely in your browser, so your JSON never leaves your machine.

What this JSON to Python converter produces

• Pydantic BaseModel classes (with the required imports) for validation and FastAPI.
• Dataclasses (@dataclass) or TypedDicts when you prefer the standard library.
• Nested classes for nested objects, defined before they are used.
• Inferred types: str, int, float, bool, List[...], and Any for unknown or null values.

How to convert JSON to Python

1. Paste your JSON into the left editor (or click Load Sample).
2. Choose an Output style — Pydantic, dataclass, or TypedDict.
3. Click Generate Models, then copy or download the Python classes.

Example: JSON to Pydantic model

Input:

{ "id": 7, "user": { "name": "Ava", "tags": ["x", "y"] }, "score": 9.5 }

Generated Python (Pydantic):

from pydantic import BaseModel
from typing import List


class User(BaseModel):
    name: str
    tags: List[str]


class Root(BaseModel):
    id: int
    user: User
    score: float

JSON to Python type mapping

• JSON string → str
• JSON integer → int
• JSON number (float) → float
• JSON boolean → bool
• JSON array → List[...]
• JSON object → a nested class
• JSON null / unknown → Any

FAQs

Can it generate Pydantic models?
Yes. Select the Pydantic output style to get BaseModel classes with the right imports. You can also choose dataclass or TypedDict.

How are nested objects and arrays handled?
Nested objects become their own classes (defined before they are referenced), and arrays become List[...] of the element type.

Do the field names match my JSON keys?
By default the tool keeps your JSON keys as the field names so the models parse your data directly. Keys that are not valid Python identifiers are adjusted.

Is my data uploaded?
No. Everything runs locally in your browser.