Is my JSON data uploaded to a server?

No. The conversion runs entirely in your browser with JavaScript. Nothing is sent over the network, which makes the tool safe for sensitive data.

Why Pydantic models rather than dataclasses?

Pydantic is the de facto standard for validating JSON from APIs — it powers FastAPI. The generated BaseModel classes validate your data at runtime, not just type-check it.

How are camelCase keys handled?

Field names are converted to snake_case, the Python convention, and the original key is preserved with Field(alias="...") so parsing keeps working.

JSON to Python (Pydantic) Converter

JSON to Python (Pydantic) Converter — Free Tool

Generate Pydantic models from JSON instantly in your browser. Free and private: your data never leaves your device.

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Root name

Style

JSON input

Python output

Why convert JSON to Pydantic models?

You have a JSON payload from an API and want typed, validated Python objects. Paste it above and get ready-to-use Pydantic models: nested objects become nested classes, camelCase keys are aliased to snake_case fields, and integers are distinguished from floats.

How it works

The converter infers the structure of your JSON locally and emits one Pydantic BaseModel per object, children first so every reference is already defined. Lists with mixed content become precise union types like list[int | str].

Frequently asked questions

Is my JSON data uploaded to a server?: No. The conversion runs entirely in your browser with JavaScript. Nothing is sent over the network, which makes the tool safe for sensitive data.
Why Pydantic models rather than dataclasses?: Pydantic is the de facto standard for validating JSON from APIs — it powers FastAPI. The generated BaseModel classes validate your data at runtime, not just type-check it.
How are camelCase keys handled?: Field names are converted to snake_case, the Python convention, and the original key is preserved with Field(alias="...") so parsing keeps working.