When you check your website on Google page speed optimizer, many of the websites are now showing no speed optimisation. That means the speed is unavailable both for mobile and desktop users. This development came just 1 day after the announcement of Google that it has upgraded the PageSpeed Insights tool to use data from the Chrome user experience report.
This is mostly happening for smaller sites that get less traffic that of larger site. Why is Google showing “unavailable”? This is because they do not have the adequate data to measure the page speed of that page yet.
See the forum discussion at Twitter.