Front-end Performance Rule #6: place your JavaScript at the bottom of your page
According to the book High Performance Web Sites: Essential Knowledge for Front-End Engineers by Steve Sonders, and at BEST PRACTICES FOR SPEEDING UP YOUR WEB SITE, there is a best practice for boosting front-end performance as follows: The problem caused by scripts is that they block parallel downloads. The HTTP/1.1 specification suggests that browsers download no more…