Performance test matters because it is a key factor in user experience. When users get an immediate response, such as a click, a successful login, or confirmation, they are more likely to stay on the page. This fast response is commonly referred to as website speed. Search engines like Google check website speed and interactivity to make sure searchers only see high-quality sites. So beyond building a better user experience, speed tools help you make your site more attractive to search engines – win-win.