Prerendered pages can skew statistics, showing more visitors
Google Chrome seems to be losing some steam lately. In fact, it's even losing market share, albeit a very small amount. But it may not have anything to do with less people using Google Chrome and instead have to do with the way the visits are counted.Google has the ability of prerendering pages that it believes users are going to load. Of course, the prediction technology can't guess right 100 percent of the time, so some pages are loaded even though they are never actually visited or wanted by the user.
This can skew stats unless accounted for. Net Applications, the company that has been showing a decline in Chrome's market share, found that pages loaded by the prerendering mechanism made up 4.3 percent of daily unique visitors for Chrome.
That's quite a large number, thankfully, WebKit, the rendering engine powering Chrome, enables website to query the state of a page, i.e. if it's visible to the user, if it's "hidden" - open in a background tab, or if it's being prerendered.
Chrome 13 debuted the prerendering technology, but it only worked on domains that supported it, Google.com at the time.
"Chrome has expanded the behavior in version 17 to include search queries typed into the omnibox," Net Applications explained.
"Chrome is the only major desktop browser that currently has this feature, which creates unviewed visits that should not be counted in Chrome’s usage share. However, the pages that are eventually viewed by the user should be treated normally," it said.
"Within the sites in our network, prerendering in February 2012 accounted for 4.3% of Chrome's daily unique visitors. These visits will now be excluded from Chrome's desktop browser share," it added.
This adjustment may explain Chrome's dwindling market share in the past couple of months, if only partially. It may be that Chrome isn't actually losing market share, rather it was over-counted previously.
At the same time, analytics companies that don't take into account pre-rendering may be inflating Chrome numbers.