Ad blocking and Web Quality of Experience

We present the first detailed analysis of ad-blocking’s impact on user Web quality of experience (QoE). We use the most popular webbased ad-blocker to capture the impact of ad-blocking on QoE for the top Alexa 5,000 websites. We find that ad-blocking reduces the number of objects loaded by 15% in the median case, and that this reduction translates into a 12.5% improvement on page load time (PLT) and a slight worsening of time to first paint (TTFP) of 6.54%. We show the complex relationship between ad-blocking and quality of experience – despite the clear improvements to PLT in the average case, for the bottom 10 percentile, this improvement comes at the cost of a slowdown on the initial responsiveness of websites, with a 19% increase to TTFP. To understand the relative importance of this tradeoff on user experience, we run a large, crowdsourced experiment with 1,000 users in Amazon Turk. For this experiment, users were presented with websites for which adblocking results in both, a reduction of PLT and a significant increase in TTFP. We find, surprisingly, 71.5% of the time users show a clear preference for faster first paint over faster page load times, hinting at the importance of first impressions on web QoE.

You may want to look at our latest paper for the details!


Fabián E. Bustamante, Faculty PI

James Newman


  • James Newman and Fabián E. Bustamante The Value of First Impressions: The Impact of Ad-Blocking on Web QoE. In Proc. of PAM 2019.


Soon we will make available the dataset from our controlled experiment with the top 5,000 Alexa websites an the 1,000-user crowdsourced experiment.