Download websites that use Uvicorn

About Uvicorn

Almost nobody points a browser at Uvicorn on purpose. The Web servers here is an ASGI server for Python applications, built to run asynchronous code behind something else, and the ordinary production shape puts a reverse proxy or a delivery network in front of it. So when we do record it, we are looking at a server that was left to answer for itself, or at a proxy configured to pass the identity of the thing behind it straight through.

The bias in that is severe and worth stating before any number is read. Most deployments of this server are invisible to us. What stays visible skews toward interfaces, internal tools, developer infrastructure and smaller deployments where nobody trimmed the response headers, so our figure is a floor on the technology and not a measurement of the application population sitting behind it.

As of September 2026 we detect Uvicorn on 21,781 sites. The project has been available since 2017 under the BSD license and is written in Python, and its spread tracks the rise of the asynchronous web frameworks it was built to serve rather than any marketing push of its own.

A match still says something precise, which is what makes the thin population useful. A domain answering this way is running Python, running it in an asynchronous stack, and running it on infrastructure that somebody configured deliberately. No hosted site builder is implied, no content management vendor, no page builder and no marketing suite. The set therefore reads as a list of engineering-led properties, which is exactly the audience that observability vendors, application security products, hosting and platform companies and technical recruiters spend their time trying to isolate from the rest of the web.

Checking one host confirms one host. An extract lets you join the whole set against company records, filter by country or domain suffix, look at what else runs alongside on the same domains, and compare successive releases of the data to tell an expanding stack from a stable one. We publish no version or vendor detail for Uvicorn, since the server tends to identify itself by name and rarely by release, and no country or version filter should be expected from these rows.