Free PythonAnywhere Alternatives

Heroku is a cloud application platform for Ruby, Rails, Node.js, Java, Python, Scala and Clojure web apps. Everything you need to build, run, and scale:

Render is a modern cloud provider that makes it effortless and instant to deploy your code in production.

With working example apps to remix, a code editor to modify them, instant hosting and deployment - anybody can build a web app on Glitch.

Google App Engine is a free* platform for developing and hosting web applications in Google-managed data centers. App Engine offers fast development and deployment; simple administration, with no need to worry about hardware, patches or backups; and effortless scalability.

ideone.com is a... pastebin. But a pastebin like no other on the Internet. More accurate expression would be

Codiad is an open source, web-based, cloud IDE and code editor with minimal footprint and requirements

goormIDE is a powerful cloud IDE service to maximize the productivity for developers and teams.

Atheos is a web-based IDE framework with a small footprint and minimal requirements, built on top of Codiad by FluidByte and the Codiad Team.

A lightweight yet powerful IDE/code editor that comes in both Web and desktop editions, the latter written with PHP and including choices for several platforms (Windows, Linux, Mac).

Koding is a self-hosted development environment for teams to come together and code in the browser. Developers can work, collaborate, write and run apps without jumping through hoops and spending unnecessary money.