Hello Bar uses javascript to run on your website. Even though it does load every time a visitor clicks on your site, the amount of time it adds is very similar to having Google Analytics installed. In other words, you should not notice a perceivable load time for Hello Bar. Add-ons to your website such as chat tools and large, unoptimized images, are usually the culprits. See how close the load time is below according to Hello Bar's website.