Why Place Bootstrap.js in the Head

Place the Bootstrap.js synchronously in the HEAD section of your HTML in a blocking manner.

Blocking and non-blocking tags determine when a tag executes, that is, either before or after the web page appears.

Ensighten has a place to put code that must execute before displaying the page.
You can swap content based on the same variables. This is especially useful with testing & optimization tools such as Test&Target, and performed to avoid flickering effects.
You can use dynamic redirecting and data passing. You can decide in real-time where to send a user based on a variable such as a referrer or cookie, or data in conditions within Ensighten.
You can include stylesheets or cross-browser compatibility shims that address issues on the site. This was used by one of our eCommerce customers to fix a shopping cart that was unexpectedly broken by a scheduled IT build.
You can deploy performance-measuring tools since many tools need to deploy as close to the start of the page load as possible.
You can provide the fastest execution for critical tags such as, analytics. We have found that executing a tag at the bottom of the page can lead to between 5-10% data loss! Late loading code can cause inconsistencies with user interaction tracking tools such as, link tracking, AJAX tracking, and others.