Bing follows Google's lead in favoring mobile-friendly sites in search results

Last month Google announced a series of changes to the way it handled search results on mobile devices, and now Microsoft is following suit. Now there is a focus on promoting those sites that are optimized for viewing on a smaller screen. Microsoft said six months ago that it would start to push mobile-friendly sites, and today this plan is being put into action.

The project started off by simply highlighting mobile-friendly sites to aid identification, but now they will be promoted further up search rankings. If there are two sites rated equally highly for their content, the one which is considered most suitable for viewing on a mobile device will appear higher in results when a search is conducted from a mobile device.

Microsoft says that the new approach "balances the need to improve the ranking for mobile-friendly pages, with the continued focus on delivering the most relevant results for a given query", pointing out that "webpages that are highly relevant to the given query that are not yet mobile-friendly will not get penalized". The transition to the new method of handling search results will not be immediate -- Microsoft expects the rollout to start in a few months.

With Google's dominance of the search market -- both mobile and non-mobile -- any changes made by Microsoft in this field will affect far fewer people. But at the same time it does indicate that web developers are being increasingly encouraged to consider the fact that their sites may be viewed on a range of different screen sizes. Unlike Google, Microsoft goes some way to explain the factors that influence how its search results are worked out.

To be rated as mobile-friendly, sites need to feature large and obvious navigation elements, include text formatted for small screens, require only vertical scrolling, and general mobile browser compatibility is also factored in. Microsoft warns website owners:

There are more factors that we are considering along the lines of mobile friendliness, like the friction that pop-ups sometimes create in navigating to the core content of the page. One important thing to remember -- we depend on access to all the necessary CSS and script files required by your page to make this determination. So, it is important that you allow Bingbot mobile user agents access to download these resources.