UC Riverside

Despite web access on mobile devices becoming commonplace, users continue to experience poor web performance on these devices. Traditional approaches for improving web performance face an uphill battle due to the fundamentally conflicting trends in user expectations of lower load times and richer web content. Embracing the reality that page load times will continue to be higher than user tolerance limits for the foreseeable future, we ask: How can we deliver the best possible user experience?

To establish the positive correlation between rich webpage content and high webpage load times, we perform the first known measurement-driven study of the complexity of web pages and its impact on performance. To mirror a client-side view, we use browser-based measurements of over 2000 websites from 4 geo-diverse vantage points over a 3 week period. We find that we can accurately predict page load times using a handful of metrics, with the number of resources requested (content richness) being the most critical factor.

Given the rising amount of webpage content and webpage load time, strategic reprioritization of content offers a parallel avenue to better the user's page load experience. To this end, we present Klotski, a system that prioritizes the content most relevant to a user's preferences. In designing Klotski, we address several challenges in: (1) accounting for inter-resource dependencies on a page; (2) enabling fast selection and load time estimation for the subset of resources to be prioritized; and (3) developing a practical implementation that requires no changes to websites. Across a range of user preference criteria, Klotski can significantly improve the user experience relative to native websites.

Finally, we investigate the potential to further improve the user experience over that offered by Klotski by pushing all content on a web page to any client attempting to load a page, but find that this offers little to no improvement in page load times due to limited capabilities of the client to consume the pushed content. This result reinforces Klotski's focus on limited resource reprioritization for fixed time period goals.