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Tests Pypi Language grade: C/C++ Language grade: Python


🚧 FastWSGI is still under development.

FastWSGI is an ultra fast WSGI server for Python 3.

Its written in C and uses libuv and llhttp under the hood for blazing fast performance.

Supported Platforms

Platform Linux MacOs Windows


FastWSGI is one of the fastest general use WSGI servers out there!

For a comparison against other popular WSGI servers, see


Install using the pip package manager.

pip install fastwsgi

Quick start

Create a new file with the following:

import fastwsgi

def app(environ, start_response):
    headers = [('Content-Type', 'text/plain')]
    start_response('200 OK', headers)
    return [b'Hello, World!']

if __name__ == '__main__':, host='', port=5000)

Run the server using:


Or, by using the fastwsgi command:

fastwsgi example:app

Example usage with Flask

See for more details.

import fastwsgi
from flask import Flask

app = Flask(__name__)

def hello_world():
    return 'Hello, World!', 200

if __name__ == '__main__':, host='', port=5000)


To run the test suite using pytest, run the following command:

python3 -m pytest


Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests where appropriate.

Significant Contributions

Special thank you to the following individuals who have made significant contributions to FastWSGI:


  • Comprehensive error handling
  • Complete HTTP/1.1 compliance
  • Unit tests running in CI workflow