Welcome to AIOHTTP

Asynchronous HTTP Client/Server for asyncio and Python.

Current version is 3.8.5.

Key Features

Library Installation

$ pip install aiohttp

You may want to install optional cchardet library as faster replacement for charset-normalizer:

$ pip install cchardet


Note that the cchardet project is known not to support Python 3.10 or higher. See #6819 and GitHub: PyYoshi/cChardet/issues/77 for more details.

For speeding up DNS resolving by client API you may install aiodns as well. This option is highly recommended:

$ pip install aiodns

Installing all speedups in one command

The following will get you aiohttp along with cchardet, aiodns and Brotli in one bundle. No need to type separate commands anymore!

$ pip install aiohttp[speedups]

Getting Started

Client example

import aiohttp
import asyncio

async def main():

    async with aiohttp.ClientSession() as session:
        async with session.get('http://python.org') as response:

            print("Status:", response.status)
            print("Content-type:", response.headers['content-type'])

            html = await response.text()
            print("Body:", html[:15], "...")


This prints:

Status: 200
Content-type: text/html; charset=utf-8
Body: <!doctype html> ...

Coming from requests ? Read why we need so many lines.

Server example:

from aiohttp import web

async def handle(request):
    name = request.match_info.get('name', "Anonymous")
    text = "Hello, " + name
    return web.Response(text=text)

app = web.Application()
app.add_routes([web.get('/', handle),
                web.get('/{name}', handle)])

if __name__ == '__main__':

For more information please visit Client and Server pages.

What’s new in aiohttp 3?

Go to What’s new in aiohttp 3.0 page for aiohttp 3.0 major release changes.


Polls tutorial

Source code

The project is hosted on GitHub

Please feel free to file an issue on the bug tracker if you have found a bug or have some suggestion in order to improve the library.


  • Python 3.6+

  • async_timeout

  • attrs

  • charset-normalizer

  • multidict

  • yarl

  • Optional cchardet as faster replacement for charset-normalizer.

    Install it explicitly via:

    $ pip install cchardet
  • Optional aiodns for fast DNS resolving. The library is highly recommended.

    $ pip install aiodns

Communication channels

aio-libs discourse group: https://aio-libs.discourse.group

Feel free to post your questions and ideas here.

gitter chat https://gitter.im/aio-libs/Lobby

We support Stack Overflow. Please add aiohttp tag to your question there.


Please read the instructions for contributors before making a Pull Request.

Authors and License

The aiohttp package is written mostly by Nikolay Kim and Andrew Svetlov.

It’s Apache 2 licensed and freely available.

Feel free to improve this package and send a pull request to GitHub.

Policy for Backward Incompatible Changes

aiohttp keeps backward compatibility.

After deprecating some Public API (method, class, function argument, etc.) the library guaranties the usage of deprecated API is still allowed at least for a year and half after publishing new release with deprecation.

All deprecations are reflected in documentation and raises DeprecationWarning.

Sometimes we are forced to break the own rule for sake of very strong reason. Most likely the reason is a critical bug which cannot be solved without major API change, but we are working hard for keeping these changes as rare as possible.

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