Google has shared new details on how it uses the Speculation Rules API to speed up clicks on search results.
When searching in Chrome, Google preloads parts of a webpage before you click, leading to faster load times.
Here’s an overview of how it works and the benefits Google has observed.
How Prefetching Works
Google loads the top two search results before you click them. When you see the results on the screen, your browser automatically fetches these links.
If you click on one, it will already be partially loaded, reducing your wait time.
Google explains:
“Google Search has been making use of the Speculation Rules API to improve navigation speed from the search results page to the result links and they’ve been using a few features of the API that may be of interest to other site owners.”
Early on, one of Google’s primary tactics was:
“One of the first uses of speculation rules was to prefetch the first two search results.”
In other words, your browser quietly fetches the HTML from the top search results as soon as you land on the results page, giving you a head start if you decide to click.
Performance Gains
Tests show a noticeable speed boost.
On Chrome for Android, Google recorded a 67-millisecond drop in Largest Contentful Paint (LCP), while Desktop Chrome users saw a 58.6-millisecond improvement.
Beyond prefetching the top two results, Google selectively prefetches other results when a user’s cursor hovers over them on desktop:
“[The Speculation Rules API] was enhanced with an eagerness property that allows speculations to only happen when the user hovers on, or starts to click a link. Google Search decided to move beyond the first two search results and also prefetch remaining search results—but only when the user hovers over the link…”
The hover action triggers a moderate prefetch, saving bandwidth for links that might not be clicked.
Mobile devices, however, lack hover functionality, so Google didn’t see the same benefits there.
Future Experiments & Browser Support
Google is exploring prerendering entire search results pages (SERPs) in certain scenarios, such as when you start typing a search in Chrome’s address bar.
Other search engines can adopt this technology, too, but Google remains the main implementer for now.
The Speculation Rules API currently works in Chromium-based browsers like Chrome.
Why This Matters
Prefetching can shave critical milliseconds off your page load time.
Google notes that even slight speed boosts matter, especially with billions of daily searches.
If your audience primarily uses Chrome, you could see performance gains by implementing the Speculation Rules API on your site.
Featured Image: Thaspol Sangsee/Shutterstock
