---
id: fastjsonschema
version: "2.22.1"
license: BSD-3-Clause
license_treatment: permissive
maintenance: active
---

# fastjsonschema — Fastest Python implementation of JSON schema

License: permissive · Maintenance: active · Popularity: top 1,000 on PyPI

## Install

pip install fastjsonschema
uv add fastjsonschema
poetry add fastjsonschema

## Description

===========================
Fast JSON schema for Python
===========================

|PyPI| |Pythons|

.. |PyPI| image:: https://img.shields.io/pypi/v/fastjsonschema.svg
   :alt: PyPI version
   :target: https://pypi.python.org/pypi/fastjsonschema

.. |Pythons| image:: https://img.shields.io/pypi/pyversions/fastjsonschema.svg
   :alt: Supported Python versions
   :target: https://pypi.python.org/pypi/fastjsonschema

See `documentation <https://horejsek.github.io/python-fastjsonschema/>`_.

## AI interpretation — verify before relying

fastjsonschema validates JSON data against JSON Schema specifications with a focus on speed, compiling schemas into optimized Python validation code.

Verdict: fastjsonschema is a production-stable, actively maintained validator with zero known vulnerabilities, no dependencies, and permissive licensing. It's a low-friction choice for JSON Schema validation in modern Python projects.

[View on SkillFed](https://skillfed.io/packages/fastjsonschema) · [View on PyPI](https://pypi.org/project/fastjsonschema/)