WordPress Releases A Performance Plugin For “Near-Instant Load Times”
WordPress has released an official performance plugin that provides support for the Speculative Loading API, an advanced technology that accelerates webpage loading times. This plugin can enhance site performance and improve the user experience for visitors by reducing page loading times.
Speculative Loading
Rendering is the process of constructing an entire webpage to enable it to appear instantly. It is achieved by downloading the HTML, images, and other resources and integrating them to create a webpage. On the other hand, prerendering involves constructing a webpage in the background before it is displayed.
With this plugin, the browser can prerender the entire webpage that a user is likely to navigate to next. The plugin predicts which webpage the user may visit based on their hovering position. It is noteworthy that Chrome has a preference to initiate prerendering only when there is an 80% probability of a user navigating to another webpage. The official Chrome support page for prerendering explains:
“Pages should only be prerendered when there is a high probability the page will be loaded by the user. This is why the Chrome address bar prerendering options only happen when there is such a high probability (greater than 80% of the time).
There is also a caveat in that same developer page that prerendering may not happen based on user settings, memory usage, and other scenarios (more details below about how analytics handles prerendering).
The Speculative Loading API solves a problem that previous solutions could not because in the past they were simply prefetching resources like JavaScript and CSS but not prerendering the entire webpage.
The official WordPress announcement explains it like this:
Introducing the Speculation Rules API
The Speculation Rules API is a new web API that solves the above problems. It allows defining rules to dynamically prefetch and/or prerender URLs of certain structures based on user interaction, in JSON syntax—or other words, speculatively preload those URLs before the navigation. This API can be used, for example, to prerender any links on a page whenever the user hovers over them.”
The official WordPress page about this new functionality describes it:
“The Speculation Rules API is a new web API… It allows defining rules to dynamically prefetch and/or prerender URLs of certain structures based on user interaction, in JSON syntax—or other words, speculatively preload those URLs before the navigation.
This API can be used, for example, to prerender any links on a page whenever the user hovers over them. Also, with the Speculation Rules API, “prerender” actually means to prerender the entire page, including running JavaScript. This can lead to near-instant load times once the user clicks on the link as the page would have most likely already been loaded in its entirety. However, that is only one of the possible configurations.”
The new WordPress plugin adds support for the Speculation Rules API. The Mozilla developer pages, a great resource for HTML technical understanding describes it like this:
“The Speculation Rules API is designed to improve performance for future navigations. It targets document URLs rather than specific resource files, and so makes sense for multi-page applications (MPAs) rather than single-page applications (SPAs).
The Speculation Rules API provides an alternative to the widely-available <link rel=”prefetch”> feature and is designed to supersede the Chrome-only deprecated <link rel=”prerender”> feature. It provides many improvements over these technologies, along with a more expressive, configurable syntax for specifying which documents should be prefetched or prerendered.”
Performance Lab Plugin
The WordPress performance team developed a new plugin for users to test before it can be included in the WordPress core. This is an opportunity to be the first to try out new performance technologies.
