Google gave webmasters plenty of warning — more than a year — but it now appears they are ready to step up efforts on indexing mobile websites and serving results based on what they find. Currently, Google’s crawling, indexing, and ranking algortihms look at desktop version. Now, they will switch to mobile-first indexing.

“Mobile-first indexing means that we’ll use the mobile version of the content for indexing and ranking, to better help our — primarily mobile — users find what they’re looking for,” Google said in a blog post. Snippets and Google cache pages will be from mobile versions of websites.

Failing to use responsive design and correctly implementing dynamic serving will cause problems with the indexing. Here’s what else Google recommends you check:

  • Make sure the mobile version of the site also has the important, high-quality content. This includes text, images (with alt-attributes), and videos — in the usual crawlable and indexable formats.
  • Structured data is important for indexing and search features that users love: it should be both on the mobile and desktop version of the site. Ensure URLs within the structured data are updated to the mobile version on the mobile pages.
  • Metadata should be present on both versions of the site. It provides hints about the content on a page for indexing and serving. For example, make sure that titles and meta descriptions are equivalent across both versions of all pages on the site.
  • No changes are necessary for interlinking with separate mobile URLs (m.-dot sites). For sites using separate mobile URLs, keep the existing link rel=canonical and link rel=alternate elements between these versions.
  • Check hreflang links on separate mobile URLs. When using link rel=hreflang elements for internationalization, link between mobile and desktop URLs separately. Your mobile URLs’ hreflang should point to the other language/region versions on other mobile URLs, and similarly link desktop with other desktop URLs using hreflang link elements there.
  • Ensure the servers hosting the site have enough capacity to handle potentially increased crawl rate. This doesn’t affect sites that use responsive web design and dynamic serving, only sites where the mobile version is on a separate host, such as