Ultra fast implementation of asyncio event loop on top of libuv.
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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.


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 performance.


uvloop requires Python 3.5 and is available on PyPI. Use pip to install it:

$ pip install uvloop

Using uvloop

To make asyncio use uvloop, you can install the uvloop event loop policy:

import asyncio
import uvloop

Alternatively, you can create an instance of the loop manually, using:

loop = uvloop.new_event_loop()

Development of uvloop

To build uvloop, you'll need Cython and Python 3.5. The best way is to create a virtual env, so that you'll have cython and python commands pointing to the correct tools.

  1. git clone --recursive git@github.com:MagicStack/uvloop.git
  2. cd uvloop
  3. make
  4. make test


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