---
id: orjson
version: "3.11.9"
license: MPL-2.0 AND (Apache-2.0 OR MIT)
license_treatment: copyleft
maintenance: active
---

# orjson — Fast, correct Python JSON library supporting dataclasses, datetimes, and numpy

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

## Install

pip install orjson
uv add orjson
poetry add orjson

## Description

# orjson

orjson is a fast, correct JSON library for Python. It
[benchmarks](https://github.com/ijl/orjson?tab=readme-ov-file#performance) as the fastest Python
library for JSON and is more correct than the standard json library or other
third-party libraries. It serializes
[dataclass](https://github.com/ijl/orjson?tab=readme-ov-file#dataclass),
[datetime](https://github.com/ijl/orjson?tab=readme-ov-file#datetime),
[numpy](https://github.com/ijl/orjson?tab=readme-ov-file#numpy), and
[UUID](https://github.com/ijl/orjson?tab=readme-ov-file#uuid) instances natively.

[orjson.dumps()](https://github.com/ijl/orjson?tab=readme-ov-file#serialize) is
something like 10x as fast as `json`, serializes
common types and subtypes, has a `default` parameter for the caller to specify
how to serialize arbitrary types, and has a number of flags controlling output.

[orjson.loads()](https://github.com/ijl/orjson?tab=readme-ov-file#deserialize)
is something like 2x as fast as `json`, and is strictly compliant with UTF-8 and
RFC 8259 ("The JavaScript Object Notation (JSON) Data Interchange Format").

Reading from and writing to files, line-delimited JSON files, and so on is
not provided by the...

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