You can, with pyodine: https://github.com/pyodide/pyodide https://github.com/pyodide/pyodide Here is an example instance: https://notebook.basthon.fr/ https://

You can, with pyodine: https://github.com/pyodide/pyodide https://github.com/pyodide/pyodide Here is an example instance: https://notebook.basthon.fr/ https://notebook.basthon.fr/ The thing is, creating a whole stack in pure JS would be very hard, since the current scientific stacks uses a lot of fortran, assembly and C with python to bind them all. Or julia. It's millions of man hours we are talking about. So compiling Python into WASM is probably the best deal for such an app. For the regular web, it would be a deal breaker: you don't want to load 15 mo of runtime before being able to interact with a web page. But for such a scientific app, it's not a problem. Besides, were you to write it entirely in JS, the size would be huge as well.