Starting April 21, 2015, Google Search will be expanding its use of mobile-friendliness as a ranking signal. This change will affect mobile searches in all languages worldwide and will have a significant impact in Google Search results. Users will find it easier to get relevant, high quality search results optimized for their devices. To help you make sure your website is ready for this search change, we've put together the following frequently asked questions:
Will this change affect my desktop traffic? No. This change will affect mobile searches in all languages worldwide.
How can I check if my site is mobile-friendly? You can check your site by testing your pages with the Mobile-Friendly Test tool. This tool shows how Google Search sees your pages. To get a list of mobile usability issues across your sites, log in to your Search Console account and use the Mobile Usability Report.
How can I make my site mobile-friendly? Get started with the guide to mobile-friendly sites to build your mobile-friendly site. If you need more customized advice for publishers, you can check out the AdSense Multi-Screen Starter Guide.