9 Python Web Servers to Power Your Next Web App

As a Python developer, deploying your web application requires a production-grade web server to handle requests from clients reliably at scale.

There are several solid options to choose from – some are barebones HTTP servers while others are full-fledged frameworks.

This comprehensive guide will explore the 9 most popular Python web servers used by professional developers today. I‘ll share my insights as a Python geek on their key features, use cases and performance.

By the end of this guide, you‘ll have the knowledge to pick the right web server for your next Python project!

Why Do You Need a Web Server?

When you build a web application in Python, you need a web server to:

• Listen to requests from clients on a port
• Parse request data like HTTP method, URL, headers, cookies, body
• Fetch requested resources like HTML files, scripts, images
• Return responses with proper status codes
• Set response headers like Content-Type, Set-Cookie etc.
• Send back response payload to client

Most Python frameworks like Django and Flask have a development web server built-in that you can use for testing.

But for production deployments, you need a high-performance web server that can handle real-world traffic securely and reliably.

Understanding WSGI and ASGI

Most Python frameworks provide a WSGI application as the entry point into the framework.

WSGI (Web Server Gateway Interface) is a standard interface for Python web apps to communicate with web servers.

WSGI has some limitations:

• It handles requests sequentially and blocks on I/O.
• No support for concurrency or parallelism.

ASGI (Asynchronous Server Gateway Interface) is the next evolution of WSGI:

• Supports asyncio for asynchronous, non-blocking I/O.
• Can handle multiple requests concurrently.
• Better scalability and throughput.

So newer Python web servers are starting to adopt ASGI.

9 Best Python Web Servers

Based on my experience in Python web development, here are the top 9 production-grade web servers to deploy your apps.

1. Uvicorn

Uvicorn is a blazing fast ASGI server implemented in Python. It‘s commonly used to deploy FastAPI web frameworks.

To install Uvicorn:

pip install uvicorn

As a Python geek, I love Uvicorn for its performance and robustness.

Key Features:

• Implements ASGI standard for Python async web apps
• Supports HTTP/1.1, HTTP/2 and WebSockets protocols
• Extremely high performance – uses uvloop and httptools under the hood
• Command-line interface for control and debugging
• Highly scalable – great for microservices architecture

Uvicorn is my go-to choice for deploying FastAPI apps due to its raw speed and active development.

2. Gunicorn

If you‘ve ever deployed Django or Flask apps, chances are you used Gunicorn. It‘s a mature WSGI-based HTTP server used widely in production environments.

To install Gunicorn:

pip install gunicorn

Here‘s why I recommend Gunicorn, based on experience:

Key Features:

• Robust process management with multiprocessing and load balancing
• Easy to integrate with Nginx reverse proxy for security
• Supports HTTP, WSGI, ASGI applications
• Highly configurable via command line args and config file
• Extensible using custom worker classes

Gunicorn is battle-tested and reliable for scaling Python web apps.

3. CherryPy

CherryPy is a minimalist Python object-oriented web framework that has a built-in multi-threaded WSGI server.

To install CherryPy:

pip install CherryPy

It‘s one of my favorite Python servers because:

Key Features:

• Elegant object-oriented design, easy to learn
• Production-ready multi-threaded HTTP server
• Built-in tools for caching, encoding, authorization etc.
• Highly extensible using plugins
• Can deploy web apps and APIs as Windows services

For small to medium web apps, CherryPy is a great choice.

4. Daphne

Daphne is an ASGI-based HTTP server originally built to power Django Channels and add WebSocket support.

To install it:

pip install daphne

Daphne has some cool features:

Key Features:

• Designed for HTTP, HTTP2 and WebSocket protocol handling
• Integrates with Django Channels for multi-process communication
• Can be used as a generic ASGI server for any framework
• Automatic application reloading in development
• Out-of-the-box HTTP/2 support with h2 protocol

If you need native WebSocket support, Daphne is a great choice.

5. Hypercorn

Hypercorn is an ASGI server for Python built on top of asyncio libraries like Trio, Quart, and h11.

To install:

pip install hypercorn

Here are some notable features:

Key Features:

• Implements HTTP/1.1, HTTP/2 and WebSockets protocols
• Leverages asynchronous I/O for high throughput
• Very fast event handling using Trio and asyncio
• SSL/TLS support included
• Helpful CLI for debugging

Overall an excellent ASGI server for modern Python web apps.

6. Twisted Web

Twisted is a mature, event-driven networking framework written in Python. Twisted Web is the web server built on top of it.

To install:

pip install twisted

Twisted Web has some cool features:

Key Features:

• High-performance asynchronous web server
• Built on top of the battle-tested Twisted engine
• Supports HTTP, WSGI, WebSockets and more
• Comes bundled with useful tools for templating, assets etc.
• Pluggable authentication, authorization and sessions

Twisted Web is a great choice if you‘re already using Twisted for networking.

7. Tornado

Tornado is a powerful Python web framework and asynchronous networking library developed by FriendFeed.

To install:

pip install tornado

As an open-source enthusiast, I like Tornado for its liberal license.

Key Features:

• High performance due to non-blocking I/O
• Supports WSGI, asyncio, callbacks for concurrency
• Well integrated with templating, authentication modules
• Built-in support for WebSockets
• Open source with a very liberal license

If you need raw performance, Tornado is a great web server.

8. AIOHTTP

AIOHTTP is a performant asynchronous HTTP client/server framework for asyncio in Python.

To install:

pip install aiohttp

I appreciate AIOHTTP for its robust tooling.

Key Features:

• Implements both HTTP client and server
• Integrated support for WebSockets
• Async and await for concurrent requests
• Handy debugging and testing tools included
• Large ecosystem of middleware and utilities

For making asynchronous HTTP calls, AIOHTTP is invaluable.

9. Meinheld

Meinheld is a high-performance WSGI-compliant Python web server written in C.

To install:

pip install meinheld

Meinheld uses some clever optimization techniques:

Key Features:

• Implements WSGI spec using C for raw speed
• Built on libev for fast event handling
• Extremely low memory footprint
• Easily embeddable in existing Python code

If you need the absolute best performance, give Meinheld a try.

Key Factors in Choosing a Python Web Server

Based on your application needs, here are some factors to evaluate when choosing a Python web server:

• Protocol support – HTTP, HTTP2, WebSocket, ASGI etc.
• Performance – throughput, latency, scalability
• Concurrency – multi-threading, async handling
• Security – HTTPS, WAF integration
• Community – maturity, documentation, ecosystem
• Features – caching, encoding, templating
• Libraries – works well with your framework of choice

For most applications, I recommend starting with Uvicorn or Gunicorn – they provide the best blend of performance, security and ecosystem support.

Bottom Line

I hope this guide gave you a comprehensive overview of the most popular and robust Python web servers used in production today.

My recommendation is to start with Uvicorn or Gunicorn and then evaluate other options like Hypercorn, Daphne or Meinheld if you need specific features.

The best web server for your Python application depends on your specific requirements around performance, concurrency, protocols and integration with existing libraries.

I highly recommend stress testing different servers early in development using load testing tools to find the optimal setup.

Let me know in the comments if you have any feedback or suggestions on other great Python web servers I should cover!