srsly

Modern high-performance serialization utilities for Python

srsly Permissive license MIT Active ★ 484 v2.5.3 released 2026-03-23

Install

srsly on PyPI

pip

pip install srsly

uv

uv add srsly

poetry

poetry add srsly

Package facts

License	MIT (permissive)
Python support	supports the current Python release (<3.15,>=3.9)
Install friction	medium — platform-specific wheel
Runtime dependencies	1 — catalogue
Maintenance	actively maintained — 143 days since the last release
Last repo commit	2026-03-27
First released	2018-12-01
Popularity	one of the top 1,000 most-downloaded packages on PyPI (30-day window, as of 2026-08-13)
Known vulnerabilities	none known (OSV.dev, checked 2026-08-13)

Evidence: srsly-2.5.3-cp310-cp310-macosx_10_9_x86_64.whl; srsly-2.5.3-cp310-cp310-macosx_11_0_arm64.whl; srsly-2.5.3-cp310-cp310-manylinux2014_aarch64.manylinux_2_17_aarch64.whl; srsly-2.5.3-cp310-cp310-manylinux2014_x86_64.manylinux_2_17_x86_64.whl; srsly-2.5.3-cp310-cp310-musllinux_1_2_aarch64.whl; srsly-2.5.3-cp310-cp310-musllinux_1_2_x86_64.whl; srsly-2.5.3-cp310-cp310-win_amd64.whl; srsly-2.5.3-cp310-cp310-win_arm64.whl; srsly-2.5.3-cp311-cp311-macosx_10_9_x86_64.whl; srsly-2.5.3-cp311-cp311-macosx_11_0_arm64.whl; srsly-2.5.3-cp311-cp311-manylinux2014_aarch64.manylinux_2_17_aarch64.whl; srsly-2.5.3-cp311-cp311-manylinux2014_x86_64.manylinux_2_17_x86_64.whl; srsly-2.5.3-cp311-cp311-musllinux_1_2_aarch64.whl; srsly-2.5.3-cp311-cp311-musllinux_1_2_x86_64.whl; srsly-2.5.3-cp311-cp311-win_amd64.whl; srsly-2.5.3-cp311-cp311-win_arm64.whl; srsly-2.5.3-cp312-cp312-macosx_10_13_x86_64.whl; srsly-2.5.3-cp312-cp312-macosx_11_0_arm64.whl; srsly-2.5.3-cp312-cp312-manylinux2014_aarch64.manylinux_2_17_aarch64.whl; srsly-2.5.3-cp312-cp312-manylinux2014_x86_64.manylinux_2_17_x86_64.whl

Development Status :: 5 - Production/StableEnvironment :: ConsoleIntended Audience :: DevelopersIntended Audience :: Science/ResearchLicense :: OSI Approved :: MIT LicenseOperating System :: MacOS :: MacOS XOperating System :: Microsoft :: WindowsOperating System :: POSIX :: LinuxProgramming Language :: CythonProgramming Language :: Python :: 3Programming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.9Topic :: Scientific/Engineering

About srsly

from the package's own PyPI description — quoted content, verbatim

srsly: Modern high-performance serialization utilities for Python

This package bundles some of the best Python serialization libraries into one standalone package, with a high-level API that makes it easy to write code that's correct across platforms and Pythons. This allows us to provide all the serialization utilities we need in a single binary wheel. Currently supports JSON, JSONL, MessagePack, Pickle and YAML.

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Read as markdown · JSON record · Source repository · Homepage

AI interpretation — verify before relying

AI-generated interpretation of the package facts above; every digit, version, license, or vulnerability id it cites is grounded in the facts already shown on this page

srsly provides a unified, high-performance API for serializing and deserializing Python objects to JSON, JSONL, MessagePack, Pickle, and YAML formats, bundling multiple serialization libraries into a single binary wheel.

Medium install friction due to compiled wheels, but well-mitigated: pre-built binaries are available for Python 3.9–3.12 across macOS, Linux, Windows, and ARM architectures. Single runtime dependency (catalogue) keeps the dependency tree lean. Active maintenance with recent releases.

MIT license permits unrestricted use, modification, and distribution in both open-source and proprietary projects, with only attribution required.

Usage

import srsly

data = {"foo": "bar", "baz": 123}
json_string = srsly.json_dumps(data)
obj = srsly.json_loads(json_string)

srsly.write_json("/path/to/file.json", data)
loaded = srsly.read_json("/path/to/file.json")

Requires Python 3.9 or later; source builds require a C compiler and development headers.

Verdict: srsly is a production-stable, actively maintained serialization toolkit with zero known vulnerabilities, minimal dependencies, and broad platform coverage via pre-built wheels. Its MIT license and top-1000 popularity make it a low-risk choice for projects needing multi-format serialization.

Needs verification

Performance benchmarks comparing srsly against individual serialization libraries for typical workloads.
Whether the bundled forks of ujson, msgpack, cloudpickle, and ruamel.yaml receive security patches independently or only via srsly releases.
Maximum Python version support beyond 3.12 given requires_python constraint.

json serialization librarymsgpack pickle yaml serializationhigh performance data serializationcross-platform serialization utilitiesjsonl file handlingpython object serializationbinary serialization formats