Monitoring and alerting on page weight to enable content producers to have an impact on page performance.
A lot has been written recently about the relation between page performance and user engagement. DoubleClick have shown that more than 53% of mobile users will leave a page if it takes more than 3 seconds to load. In addition the average size of a webpage is increasing, with the latest figures from whatdoesmysitecost.com showing an average page weight of just under 2.5 MB. Google Accelerated Mobile Pages and Facebook Instant articles have both arisen as an attempt to respond to these issues within their respective ecosystems.
Tests on Guardian content confirm that there is a significant relation between page size and time taken for a page to load. This shows that if you can manage your page size, then it becomes easier to manage your performance, and thus prevent performance-related loss of engagement.
Normal practice for monitoring page performance is to select a small number of test pages and measure them regularly using a tool like SpeedCurve to look for variations. This standard approach is effective for monitoring changes in the codebase, but only for those selected pages.