Changes to css files (and perhaps other static files) do not require reloading of server?

I have noticed that if I only make changes to my css files, they appear to work even without reloading the server. I have been reloading anyway, just in case, but maybe that is not necessary. How about changes to html templates (I am using Flask) if they do not change any of the Jinja2 parts? Reload or not? Some guidelines about when reloading is necessary or not would be helpful. Thanks.

Changes to static files that you deliver through the static mappings settings on the pythonanywhere webapp page does not require reloading of the server (but setting up a new mapping does)

For most other things that involve running actual code, you should be reloading just in case.