What is FastAPI?

Framework

FastAPI is a web framework: Modern, fast Python web framework. Tech Stack Detector identifies FastAPI on any website by analysing HTTP response headers and the HTML source.

FastAPI is a web framework (Framework), detected on 3 websites in our index. See websites using FastAPI ↓

CategoryFramework
Detection signals2 signals
In our index3 websites

How Tech Stack Detector detects FastAPI

FastAPI is matched from these signals during a single, ordinary page request. Each one contributes to the confidence score shown on a scan.

  • HeaderUvicorn ASGI server (common with FastAPI)
  • Html PatternFastAPI docs or OpenAPI spec

Detecting FastAPI also implies Python.

Websites using FastAPI

Recently scanned websites where we detected FastAPI. Open one to see its full technology stack.

Often used with FastAPI

Technologies most frequently detected alongside FastAPI across scanned websites.

Alternatives to FastAPI

Other Framework technologies Tech Stack Detector detects: popular alternatives and related tools, most-detected first.

Compare FastAPI

Side-by-side comparisons of FastAPI with other Framework technologies.

Popular technologies

The technologies most often detected across all websites scanned on Tech Stack Detector.

Frequently asked questions

What is FastAPI?

FastAPI is a web framework: Modern, fast Python web framework. Tech Stack Detector identifies FastAPI on any website by analysing HTTP response headers and the HTML source. Its official website is https://fastapi.tiangolo.com.

How can I tell if a website uses FastAPI?

Enter any URL into Tech Stack Detector and it reports whether FastAPI is present, with a confidence score and the exact evidence it matched. Detection is based on HTTP response headers and the HTML source. No login or crawling of the site is required.

What does detecting FastAPI imply?

When FastAPI is detected, Tech Stack Detector also infers Python, because FastAPI is built on top of it.

How many websites use FastAPI?

FastAPI has been detected on 3 websites in the public Tech Stack Detector scan index. This reflects sites that visitors have analysed here, not global market share.

What are some alternatives to FastAPI?

Other Framework technologies Tech Stack Detector detects include React, Next.js, Laravel, Astro, Vue.js and Nuxt. You can compare any of them side by side with FastAPI.

Data last updated October 20, 2026 · based on 618 recently scanned websites.