uvloop

0.22.1 verified Tue May 12 auth: no python install: verified quickstart: verified

uvloop is a fast, drop-in replacement for Python's built-in asyncio event loop, implemented in Cython and built on top of libuv. The current version is 0.22.1, and it follows a regular release cadence with active maintenance.

pip install uvloop

Common errors

error ModuleNotFoundError: No module named 'uvloop' ↓

cause The `uvloop` package has not been installed in the active Python environment.

fix

pip install uvloop

error error: Microsoft Visual C++ 14.0 or greater is required. Get it with 'Microsoft C++ Build Tools': https://visualstudio.microsoft.com/visual-cpp-build-tools/ ↓

cause `uvloop` is a Cython extension that requires a C compiler to build from source, which is often missing on Windows systems by default.

fix

Install the Microsoft C++ Build Tools via the provided link or Visual Studio Installer, then retry pip install uvloop.

error fatal error: 'uv.h' file not found ↓

cause When `pip` attempts to build `uvloop` from source (e.g., if a pre-built wheel isn't available), the `libuv` development headers are missing from the system.

fix

Install the libuv development package for your operating system (e.g., sudo apt-get install libuv1-dev on Debian/Ubuntu, brew install libuv on macOS).

Warnings

breaking uvloop does not support Windows at the moment. ↓

fix Consider using a different event loop implementation on Windows.

breaking uvloop may not be compatible with Python versions beyond 3.13. ↓

fix Verify compatibility with your Python version before using uvloop.

gotcha uvloop may not handle closed connections gracefully in certain scenarios. ↓

fix Implement additional error handling to manage closed connections appropriately.

Install compatibility verified last tested: 2026-05-12

python os / libc status wheel install import disk

3.10 alpine (musl) - - 0.09s 27.2M

3.10 slim (glibc) - - 0.06s 31M

3.11 alpine (musl) - - 0.20s 29.3M

3.11 slim (glibc) - - 0.14s 33M

3.12 alpine (musl) - - 0.41s 23.1M

3.12 slim (glibc) - - 0.34s 28M

3.13 alpine (musl) - - 0.41s 22.7M

3.13 slim (glibc) - - 0.33s 27M

3.9 alpine (musl) - - 0.09s 26.6M

3.9 slim (glibc) - - 0.07s 30M

Imports

uvloop
```
import uvloop
```
Ensure that uvloop is installed and imported correctly.

Quickstart verified last tested: 2026-04-23

A basic example demonstrating how to use uvloop as the event loop for asyncio applications.

import asyncio
import uvloop

async def main():
    # Your asynchronous code here
    pass

uvloop.run(main())