Given the abundance of phones, many users around the world are primarily interacting with the mobile web. Google in response is moving to mobile-first indexing for Search, and is now defaulting to that for new domains.
To keep Search results fresh and relevant, Google continuously crawls the web to index and rank websites. The company previously analyzed the desktop version of a page, but as of last year began looking at the mobile variant to provide results that are more representative of how users are interacting with the web around the world.
Mobile-first indexing with the smartphone Googlebot is used for over half of the pages in global Search results, and it is now the default for “all-new, previously unknown to Google Search, websites starting July 1, 2019.”
Google found that “new websites are generally ready for this method of crawling.” As the default state for new websites, admins will no longer be notified when mobile-indexing is used.
Mobile-first indexing has come a long way. We’re happy to see how the web has evolved from being focused on the desktop to becoming mobile-friendly, and now to being mostly crawlable and indexable with mobile user-agents!
Site owners can check for mobile-first indexing by using the URL Inspection Tool in Search Console. Otherwise, Google is still “monitoring and evaluating pages for their readiness for mobile first indexing, and will notify them through Search Console once they’re seen as being ready.”
For existing websites we determine their readiness for mobile-first indexing based on parity of content (including text, images, videos, links), structured data, and other meta-data (for example, titles and descriptions, robots meta tags). We recommend double-checking these factors when a website is launched or significantly redesigned.