How to insert response size and time into the page itself, at least partially?

Question

I realize it\'s a chicken and egg problem and that it\'s not possible to accurately resolve the time it took to render a page (or the size of response) and insert that numbe

Answer 1

Or have an asynch Javascript call that gets the response time and size from the server after its ready? Treat it like a callback to be performed after the page is done loading and the values are ready to insert.