Lazy loading of references on Russian Wikipedia

On the 1st September, lazy loading references was disabled on Russian Wikipedia after both images and references were enabled back in July. The beneficial Lazy loading of images continued to be enabled. Whereas previously all references views were routed via the API, now references would be served in the HTML.

The impact gives the impression that very few users need references in a page view. In a week period, after ending the experiment, an additional 338GB were shipped to Russian Wikipedia and there was only a 0.11GB decrease in bytes shipped via by the API.

In the worse case disabling the experiment increased page load by 2 seconds and first paint by 0.5 seconds.

Impact on performance
[ToDo: Normalise sample size]

Fully load time, first paint and first interactive time were inspected before and after the experiment was disabled.

First paint

DomInteractive

Impact on bytes shipped
The following SQL query was made on all page views for the Russian mobile site: We also had to consider the increased load on the API to retrieve references. The bytes shipped by the API before and after the change to the references api were considered using the following query: