Recently, Google announced it will be making updates to the mobile-friendly algorithm in May. The algorithm, which was launched last year in April makes use of mobile-friendliness as a ranking signal in mobile search results.
Google has started displaying a new type of warning to site owners if their site is not mobile-friendly.
This warning displays within the mobile search results to the site owner only if Google knows that searcher is the site owner.
The message appears within rich snippet of the site’s mobile search result listing as “Your page is not mobile-friendly.” The warning links to a Google help page regarding mobile-friendliness.
Google’s John Mueller told that these warnings are only an experiment to find they will help to increase mobile-friendliness or not.