If you were to work on pure JavaScript code for local and web development, what IDE would you use? Not a quality question, I'm looking for personal opinions mainly.

Because you mentioned ftp and js / web.
I'd use vsCode with remote ssh.

This will create a remote connection and setup to the dev environment (granted it has ssh setup) sand your working tree (folder tree) will be that of the remote location.

You could use something like live browser or similar to have a local (on your machine) running in a localhost environment accessible to the browser if it's purely JS based.

Vscode

VSCode for the win!

Well, as a professionnal developper, i find it a neccessarly investment to pay webstorm.
Besides i use androidstudio for android and it is the same intellij familly.
Code completion, code folding code formatting is great... And so many feature i use a lot.

I once wrote my entire 40 page static web page in sublime and uploded one by one (not event zipped) using browser even without using filezilla ftp or any other client . Go throught everything asap before its too late.

Definitely vscode

Vim.. Sorry..

VS Code (though not an IDE)

Webstorm