stucture of this page:

  external css (
  external js (
  defer external js (
  img (
  inline script
  ************************** fold ****************************
  bottom external js (
  bottom external css (

enter in some values and see how they affect page rendering

head css download (seconds)
head javascript download (seconds)
head defer javascript download (seconds)
inline script execution time (seconds)
image download (seconds)
bottom of page javascript download (seconds)
bottom css download (seconds)

inline script

************************** fold *************************