- Common form engagement tracking techniques with custom variables in Google Tag Manager - December 5, 2018
- What exactly is a doorway page anyway? - November 30, 2018
- Are you completely misreading time on site in Google Analytics? - July 11, 2016
[custom_headline type=”left, center, right” level=”h2″ looks_like=”h5″ accent=”true”] What is Prerendering?[/custom_headline]
Prerendering is an experimental feature in Chrome (versions 13 and up) that can take hints from a site’s author to speed up the browsing experience of users.
It’s a bit like Firefox’ prefetching feature aimed at speeding up page load speeds by instructing the browser to automatically fetch the resources of a linked page, before the user clicks on the click. The difference, though, is that Chrome prerendering is Firefox prefetching on steroids. Prefetching only retrieves top level resources eg the HTML, but not sub resources such as JavaScript, CSS and media files by the brower.
Prerendering gets everything, which leads to a much faster and noticeable page speed bump.
The feature can be implemented by use of the Rel=”prerender” link element. Eg:
<link rel="prerender" href="http://example.org/index.html">
Google Search Result Pages Now Using Rel=”prerender”
It’s now been detected that the Google website itself is using prerender on the position 1 result for keywords where the algorithm has determined to a high confidence level it is the most relevant result.
As you would expect, these appear frequently for branded keywords where Google search is used as a navigational tool by users instead of content discovery.
In the below screenshot, we see the rel=”prerender” link in the sourcecode for the SERP page for a branded search of “Sydney Morning Herald”
However a search for an unbranded keyword like “backpack” shows no results with rel=”prerender”.
Personalisation of Results Affects Rel=Prerender
At the current time of writing this blog post, I am only able to detect prerender when logged into a Google account. I have seen prerender show up in the past in logged out status, but am unable to replicate for the same keyword seen previously. This indicates this relatively new addition to search pages is still in a testing phase and may or may not become a permanent feature.