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JSON → Pydantic Model

Paste any JSON object and instantly get Python Pydantic BaseModel classes — with nested model support.

Input JSON
Pydantic Model
🐍

Paste JSON on the left to generate a Pydantic model

What is Pydantic?

Pydantic is the most popular data validation library for Python. It uses Python type hints to validate data and is the backbone of FastAPI, one of the most popular Python web frameworks.

How to Use This Tool

  1. Paste your JSON object or API response on the left.
  2. Pydantic model classes generate instantly on the right with syntax highlighting.
  3. Click "Copy" to grab the model code and paste it into your Python project.

Features

  • Nested Objects: Automatically creates separate classes for nested objects.
  • Type Detection: Infers str, int, float, bool, list types from values.
  • Optional Fields: Null values become Optional with default None.
  • Arrays of Objects: Detects typed lists with proper class generation.
  • PascalCase Names: Class names are auto-formatted to Python conventions.

Frequently Asked Questions

Does this work with Pydantic v2?

Yes! The generated code uses BaseModel which works with both Pydantic v1 and v2.

Can I use the output with FastAPI?

Absolutely. The generated Pydantic models can be used directly as FastAPI request/response schemas.

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