Techniques are described herein for determining an impact of slow performing webpages on a website. For example, a detection system may be provided to determine timing distributions for webpages by analyzing timing measurements for different timing metrics. The detection system may determine ranges of the timing distributions for slow and fast group of users of the website. The detection system may analyze user interactions of slow and fast group of users on the website. The detection system may further determine impacts of poor performing webpages on the website's performance based on the analysis of the user interactions on the webpages. The detection system may classify the impacts the webpages of the website and display the classifications to a website provider for identifying network operation(s) contributing to poor performance of the webpages.