Uvicorn
Lightning-fast ASGI server using uvloop and httptools.
Pricing
Free tier
Flat rate
Adoption
→StableLicense
Open Source
Data freshness
Aging · Jun 8, 2026Overview
What is Uvicorn?
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.
Key differentiator
“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.”
Capability profile
Capability Radar
Honest assessment
Strengths & Weaknesses
↑ Strengths
↓ Weaknesses
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.
Due to its specialized nature, debugging and resolving issues with Uvicorn often requires in-depth knowledge of the ASGI protocol and related concepts.
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.
Fit analysis
Who is it for?
✓ Best for
Teams building fast, asynchronous web applications with Python frameworks like FastAPI or Starlette
Developers needing a lightweight ASGI server for rapid development and deployment cycles
Projects requiring high performance and low latency in serving HTTP requests
✕ Not a fit for
Applications that require real-time streaming capabilities beyond what ASGI can offer
Teams looking for a full-featured web application framework rather than just an ASGI server
Cost structure
Pricing
Free Tier
Available
Open source — free to use
Starts at
$0
Model
Flat rate
Enterprise
None
Performance benchmarks
How Fast Is It?
Ecosystem
Relationships
Works well with
Next step
Get Started with Uvicorn
Step-by-step setup guide with code examples and common gotchas.