Here’s a very simple test that demonstrates how fast intention.js is. The page has three divs. The first is loaded with styles from the start—loaded with the DOM. The other two are given a green background and ::before content only after intention.js has registered them as intentional objects and has responded to its axes.
At page load, the second and third divs do not yet have a class. When Intention responds, they are assigned a class .loaded that gives them a green background. They are also assigned content properties specific to the context that passed.
All of these assignments, of course, should seamless with the page load, demonstrating how quick your page can dynamically restructure.