from Hacker News

Flask is a web microframework built to be used with WSGI servers and synchronous code. Quart is the same web microframework built to be used with ASGI servers and asynchronous code. In other words Flask and Quart are now the same base framework as they share the majority of their codebases.

This means that you can use the same framework API and understanding to write synchronous code with Flask, and asynchronous code with Quart.

It is important to note that Flask cannot be made asynchronous without breaking extension and backwards compatibility, or without using monkeypatching. Therefore, Quart is best viewed as a namespace for async/await usages.

Questions and comments very welcome. (I'm struggling a little thinking about how best to communicate this)