Jeffery Jose, Google Product Manager, not only announced that the page experience update is coming to desktop at Google I/O but also announced that “Google Search will prefetch websites built using signed exchanges.” He said this was announced earlier this year but can make a huge difference with your core web vitals scores. This should start happening in mid-June 2021 with the page experience update rollout.
This was spotted by Saijo George on tl;dr. At the 7:43 mark Jeffery Jose from Google said “One other way you can get page performance for your users is taking advantage of prefetching on Google Search via the use of signed exchanges.” He then explained that “earlier this year, we announced that Google Search will prefetch websites built using signed exchanges.” “Pages are prefetched and stored on the user’s browser, ready to be loaded when the user clicks on the result, leading to near instant loading,” he added.
Here is the slide:
He added that “this is possible through the use of Google’s fast cache servers, distributed around the world that you can now take advantage of without any additional cost.” He then gave this short case study “Nikkei, a large Japanese publisher, saw tremendous improvements in both performance numbers and business metrics using signed exchanges prefetching. In their tests, LCP improved by 300 milliseconds, about 20% and this was before the team did micro optimizations. In other words, 20% was the lowest hanging fruit. As a result of fast loading, they saw 12% more user engagement. Congratulations to the team for such an amazing accomplishment.”
Here is a tweet on that slide:
On Signed Exchanges (SXGs), Google Search will now crawl, cache, and prefetch them when applicable. It can improve Largest Contentful Paint (LCP) and Page Performance #GoogleIO pic.twitter.com/xF4Y8Fsu8x
— Samuel Lavoie ???? (@samuellavoie) May 18, 2021
As we noted, this goes live in mid-June 2021 with the page experience update.
Here is the video embed where this was said:
Google added signed exchange issues in Search Console recently after providing this as an option to publishers in 2019.
In 2011, Google has a Chrome based prefetching mechanism that worried webmasters, by the way.
Forum discussion at Twitter.