Welcome to AIOHTTP

Asynchronous HTTP Client/Server for asyncio and Python.

Current version is 3.9.5.

Key Features

Library Installation

$ pip install aiohttp

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 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.

Development mode

When writing your code, we recommend enabling Python’s development mode (python -X dev). In addition to the extra features enabled for asyncio, aiohttp will:

  • Use a strict parser in the client code (which can help detect malformed responses from a server).

  • Enable some additional checks (resulting in warnings in certain situations).

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.


  • async_timeout

  • attrs

  • multidict

  • yarl

  • Optional aiodns for fast DNS resolving. The library is highly recommended.

    $ pip install aiodns
  • Optional Brotli or brotlicffi for brotli (RFC 7932) client compression support.

    $ pip install Brotli

Communication channels

aio-libs Discussions: https://github.com/aio-libs/aiohttp/discussions

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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