Is it possible to search robot with JavaScript?

Question

JavaScript

I want to know if the browser can get information from the site without opening it in a tab, without displaying the site, but write information, for example, somewhere inside, and JavaScript would process it and write the information to the tab as I need?

Answer 1

It can be done as a browser extension.

Answer 2

Of course not.
The client-side script has severe restrictions regarding access to content loaded from a different domain than the current one.

Answer 3

Apparently one JS is not enough if you do not do it on NodeJS.