Debugging online js

So, just like you can do with chrome, pop up dev tools and dig around a website, with breakpoints and so on. I want to do the same with Webstorm.

I think that I managed to do that choosing the "javascript debugging" in the Debugger's option and the URL of the website I wanted to check. So far so good.

The problem is that most online *.js files are compressed and therefore unreadable (not to mention setting breakpoints). No biggie in Chrome, just "Pretty print" and it just works.

When I went to Webstorm to reformat code (basically the same thing you do in Chrome) it didn't allow me to because it was a "read-only" file. I'm well aware it is a read-only file, I only need sane formatting.

So it effectively stops any chance of examining online javascript with the bare minimums of code formatting.

How to go around this "bug"?