Slower behavior using Fast API (same gunicorn config) Gunicorn with uvicorn.workers.UvicornWorker than using default one

I’m using this dependencies:

starlette==0.13.6 uvicorn==0.11.8 fastapi==0.61.1

According to every check I’ve worked with, using FastAPI is supposed to handle more request per second than a Flask App but I’m finding different behaviors.

• Using Flask + Gunicorn, I’m getting twice the number of req/s vs using FastAPI + Gunicorn(uvicorn.workers.UvicornWorker)

The other params (besides the worker class) are the same for both apps.

What can I check to improve this ? or is this the expected behavior? If so, what could be other places I could look into to improve the performance of using FastAPI ?

[ycd]

It’s kinda hard to tell without code and how you benchmarking them (running options etc.)

Also, I did some benchmarking you might want to check it out

[ycd]

Yes, please add these,

How do you run FastAPI, and options?

• Example: uvicorn your:app --workers int

How do you run Flask, and running options?

• Example: waitress-serve --call "your:app"

The code that you use for testing FastAPI

from fastapi import FastAPI, Request

app = FastAPI()

@app.get("/etc")
async def etc(request: Request):
    return await request.body()

The code that you use for testing Flask

from flask import Flask

...

etc.