I need to debug jasvascript loaded by page. Loaded page are not locally placed.
Loaded js is packed. I want to substitute it with unpacked version.
Is there any tricks or browser options to make it?
It looks like Fiddler's AutoResponder tab will do this for you.
You say you want to replace the JS with the "unpacked" version--if you just want to insert line breaks so you can step through in a debugger, the Venkman debugger has a "Pretty Print" button which does that.