Uvicorn

What it is

Uvicorn is a high-performance ASGI web server that leverages the speed of uvloop and httptools to deliver fast response times for Python applications. It's particularly useful for developers working with frameworks like FastAPI or Starlette, offering robust performance out-of-the-box.

Uvicorn stands out as one of the fastest and most lightweight ASGI servers, making it ideal for developers who prioritize performance without sacrificing ease of use.

When it fits — and when it doesn’t

Known weaknesses

Each one links to the public issue, changelog or docs page it came from, where we have one.

1. 01

   Limited to ASGI-compatible applications

   Uvicorn is designed specifically for ASGI, which means it's not suitable for traditional WSGI-based Python web frameworks like Django or Flask without additional adapters.

2. 02

   Requires a deep understanding of ASGI to troubleshoot issues

   Due to its specialized nature, debugging and resolving issues with Uvicorn often requires in-depth knowledge of the ASGI protocol and related concepts.

3. 03

   Documentation lacks comprehensive examples for complex setups

   The official documentation focuses mainly on basic usage scenarios but falls short when it comes to more advanced configurations, leaving users to rely heavily on community forums or trial-and-error.

What it does well

• High performance with uvloop and httptools

• Built for ASGI applications

• Lightweight and easy to integrate

• Supports hot reloading for development

• Leverages Python's asyncio for non-blocking I/O

Pricing

Free tier

YesOpen source — free to use

Paid from

$0

Model

Flat rate

Enterprise plan

No

Pricing not independently confirmed — check the vendor’s page.