# JsonValidityEvaluator

> **Class** in `langchain_classic`

📖 [View in docs](https://reference.langchain.com/python/langchain-classic/evaluation/parsing/base/JsonValidityEvaluator)

Evaluate whether the prediction is valid JSON.

This evaluator checks if the prediction is a valid JSON string. It does not
    require any input or reference.

## Signature

```python
JsonValidityEvaluator(
    self,
    **_: Any = {},
)
```

## Extends

- `StringEvaluator`

## Constructors

```python
__init__(
    self,
    **_: Any = {},
) -> None
```


## Properties

- `requires_input`
- `requires_reference`
- `evaluation_name`

---

[View source on GitHub](https://github.com/langchain-ai/langchain/blob/9f232caa7a8fe1ca042a401942d5d90d54ceb1a6/libs/langchain/langchain_classic/evaluation/parsing/base.py#L17)