How to know HTML page needs to be rendered by JS compiler?
Any HTML code generated by  tags won't be retrieved by requests. 
The only way to know if a page would need to be rendered by a browser to generate the whole content is to check if its HTML code has  tags.
Still, if the information you are interested on is not generated by JS, requests.get() will serve you well.
I am trying to crawl some websites and while I am using headless chrome browser with selenium to render some HTLM that have embedded JS, I would also like to simply use requests, for the cases where there is no need for JS code rendering. 
Is there a way to know if the HTML needs to be rendered by a browser or if a simple requests.get() would give me the complete HTML content?