uvloop · Python Simple Repository Browser

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Author: Yury Selivanov

Requires Python: >=3.8.1

Classifiers

Development Status

5 - Production/Stable

Framework

AsyncIO

Intended Audience

Developers

License

OSI Approved :: Apache Software License
OSI Approved :: MIT License

Operating System

POSIX
MacOS :: MacOS X

Programming Language

Python :: 3 :: Only
Python :: 3.8
Python :: 3.9
Python :: 3.10
Python :: 3.11
Python :: 3.12
Python :: 3.13
Python :: Implementation :: CPython

Topic

System :: Networking

https://img.shields.io/github/actions/workflow/status/MagicStack/uvloop/tests.yml?branch=master

https://img.shields.io/pypi/v/uvloop.svg

uvloop is a fast, drop-in replacement of the built-in asyncio event loop. uvloop is implemented in Cython and uses libuv under the hood.

The project documentation can be found here. Please also check out the wiki.

Performance

uvloop makes asyncio 2-4x faster.

The above chart shows the performance of an echo server with different message sizes. The sockets benchmark uses loop.sock_recv() and loop.sock_sendall() methods; the streams benchmark uses asyncio high-level streams, created by the asyncio.start_server() function; and the protocol benchmark uses loop.create_server() with a simple echo protocol. Read more about uvloop in a blog post about it.

Installation

uvloop requires Python 3.8 or greater and is available on PyPI. Use pip to install it:

$ pip install uvloop

Note that it is highly recommended to upgrade pip before installing uvloop with:

$ pip install -U pip

Using uvloop

As of uvloop 0.18, the preferred way of using it is via the uvloop.run() helper function:

import uvloop

async def main():
    # Main entry-point.
    ...

uvloop.run(main())

uvloop.run() works by simply configuring asyncio.run() to use uvloop, passing all of the arguments to it, such as debug, e.g. uvloop.run(main(), debug=True).

With Python 3.11 and earlier the following alternative snippet can be used:

import asyncio
import sys

import uvloop

async def main():
    # Main entry-point.
    ...

if sys.version_info >= (3, 11):
    with asyncio.Runner(loop_factory=uvloop.new_event_loop) as runner:
        runner.run(main())
else:
    uvloop.install()
    asyncio.run(main())

Building From Source

To build uvloop, you’ll need Python 3.8 or greater:

Clone the repository:

$ git clone --recursive git@github.com:MagicStack/uvloop.git
$ cd uvloop

Create a virtual environment and activate it:

$ python3 -m venv uvloop-dev
$ source uvloop-dev/bin/activate

Install development dependencies:
```
$ pip install -e .[dev]
```
Build and run tests:
```
$ make
$ make test
```

License

uvloop is dual-licensed under MIT and Apache 2.0 licenses.

0.22.1 Oct 16, 2025

0.21.0 Oct 14, 2024

0.21.0b1 Sep 03, 2024

0.14.0rc2 Oct 29, 2019

0.14.0rc1 Oct 25, 2019

0.13.0 Aug 14, 2019

0.13.0rc1 Apr 25, 2019

0.12.2 Mar 20, 2019

0.12.1 Feb 12, 2019

0.12.0 Jan 21, 2019

0.12.0rc1 Oct 31, 2018

Wheel compatibility matrix

Platform	CPython 3.8	CPython 3.9	CPython 3.10	CPython 3.11	CPython 3.12	CPython 3.13	CPython 3.14	CPython (additional flags: t) 3.14
macosx_10_13_universal2
macosx_10_13_x86_64
macosx_10_9_universal2
macosx_10_9_x86_64
manylinux2014_aarch64
manylinux2014_x86_64
manylinux_2_17_aarch64
manylinux_2_17_x86_64
manylinux_2_28_aarch64
manylinux_2_28_x86_64
musllinux_1_2_aarch64
musllinux_1_2_x86_64