Web performance: Cache efficiency exercise

This post details a study conducted by Meta to measure the cache efficiency of facebook.com, comparing current performance to an older Yahoo study from 2007. It describes the methodology for recreating the study using a dedicated PHP endpoint and an image tag next to the Facebook search bar. The results show a cache hit rate of 84.1% (excluding Firefox v32+), an improvement over the 2007 study, but also highlight that caches do not stay populated for long, with a 42% chance of a desktop request having a cache that is at most 47 hours old. The post discusses practical applications and best practices for utilizing browser caches, concluding that despite frequent code releases, cache performance has improved and remains a critical factor for web performance.