This article by an engineer at Google explains it pretty well. My own testing has shown the same results. https://www.igvita.com/2014/05/20/script-injected-asyn

This article by an engineer at Google explains it pretty well. My own testing has shown the same results. https://www.igvita.com/2014/05/20/script-injected-async-scripts-considered-harmful/ https://www.igvita.com/2014/05/20/script-injected-async-scri...