Google is exploring a new method of improving site performance in Google Chrome, this time by adding a new back-caching feature that would keep certain data in memory, even after you’ve left a site. The company writes:
The company states that this feature could improve performance by up to 19 percent in mobile Chrome, and by 10 percent on desktop PC based on the number of site interactions that represent a back/forward usage pattern. This type of caching wouldn’t accelerate sites you visit on a regular basis or improve performance overall. It’s a specific change that would make it easier to surf when moving forward and back on the same site after having accessed it the first time.
This is a feature that Firefox and Safari already use, albeit apparently in a somewhat different way. I tried comparing Chrome and Firefox in an ordinary desktop comparison, checking the load times on several sites in succession in the same manner as the videos on Google’s developer blog. Firefox may have outperformed Chrome slightly in these tests, but not enough for me to feel comfortable declaring it a winner, and it didn’t produce the same behavior as the Chrome test did for Google. The instant load of the previous page due to bfcache doesn’t seem to happen the same way. Then again, the video is supposed to show how the feature could work in the future, not serve as a final illustration of implementation.
These changes could increase RAM usage in Chrome, but Google plans to minimize this with smarter rules about when and how to keep data in RAM while pages are suspended. The goal is to implement the feature throughout 2019 and roll it into shipping Chrome in 2020.