In November 2014, Google started labeling sites as “mobile-friendly” to denote which pages are optimized for phones. In February 2015, Google announced plans to roll out mobile ranking changes on April 21 (an unprecedented move — the company almost never announces algorithm changes in advance). A webpage is eligible for the “mobile-friendly” label if it meets the following criteria, as detected in real time by Googlebot: - Avoids software that is not common on mobile devices, like Flash - Uses text that is readable without zooming - Sizes content to the screen so users don’t have to scroll horizontally or zoom - Places links far enough apart so that the correct one can be easily tapped Get the full story at VentureBeat and TechCrunch