Before the invention of tablet computers and the corresponding increase in the number of screen sizes available, most websites catered to mobile devices by having a separate website that was designed solely for them - usually accomplished by having a separate domain (For example, "m.bbc.co.uk"). This approach had some significant disadvantages, including the fact that any links to a company's mobile-only website would not benefit the desktop-only website and vice versa. Now, most websites use "responsive" web design, meaning that the same website is displayed to all users, but that the website responds to the various screen sizes being used by changing it's layout.
Most Google searches are now performed on mobile devices but, where both a mobile- and desktop-version of a website exists, Google's ranking systems still use the desktop version of websites to decide how relevant a page is to the user's search. This can result in search results on mobile which disappoint the user because mobile-only versions of websites commonly contain less content than their desktop equivalent. That is, the user is less likely to be returned search results that provide exactly what they are looking for.
To counter this, Google has announced that it has started experimenting with a "mobile-first" philosophy, whereby it will use the mobile version of websites to evaluate their relevance to search terms instead of the desktop version, regardless of the device used. This is a significant change, and one that will almost inevitably graduate from an experimental stage into Google's core algorithms. At this stage, Christi Olson from Bing says that they currently have no plans to emulate this approach.
Here's how this change to Google's approach will affect you, depending on which of the following three scenarios your website falls into:
Interestingly, if your website uses Accelerated Mobile Pages (AMP) (in any of the three cases above),Google will not treat them as your website's default mobile version. This means that for optimal search engine rankings your non-AMP content still needs to be mobile-friendly.
Google first announced their intention to transition to a "mobile-first" index in November 2016, but in June 2017 Google's Gary Illyes estimated that this would not now start to happen until 2018. "We're thinking about how we can make sure we only include in the mobile-first index sites that won't be hurt by the mobile-first index," he said, before admitting that it might take up to five years before the process is complete.
In December 2017, Google's John Mueller explained how you could find out if your website has been moved to the mobile-first index by checking your website's log files. Normally, about 80% of the crawling is carried out by Googlebot desktop and about 20% with the smartphone Googlebot. "That will shift over and most of the crawling will be done with the smartphone Googlebot and less crawling with the desktop Googlebot," he said.
Luckily, most websites built within the last few years will have been built responsively. But if your website is not yet mobile-friendly, or your website has both mobile and desktop versions, it's time to act before your website is left behind completely in the search engine rankings. And if you are not sure which of the above scenarios your website falls into, please leave a question below or Contact Us for a consultation.
Last updated: 12th March, 2019