Reading/Web/Projects/Performance/Lazy loading images

Lazy loading images was enabled on the production beta channel on the 24th March. As an example, this led to the overall bytes served to users for images on the Barack Obama article dropping from 657kb to 169kb.

Early data shows this had a positive impact on the 95th percentile of beta anonymous and authenticated users in our global metrics but impact was less clear in our controlled tests on Barack Obama.



Predicting impact on stable
Static files emulating the lazy loaded images experience vs the current experience were uploaded to the cluster.

First view load was 38.541s for the current experience of the Barack Obama page on a 2G browser. With images lazily loaded under the same conditions first view load was 25.210s.

Interestingly, our own webpagetest jobs simulating a 2G connection record fully loaded time as already being around the 25s mark. This is being investigated.