Google has done its last mobile-first indexing switch today, a six-year process

Google started its efforts to move sites over to mobile-first indexing over six and a half years ago. Today, Google confirmed those efforts are now done, and the last batch of sites eligible for mobile-first indexing have been moved over.

Confirmation. John Mueller from Google confirmed today was the last batch on Mastodon today after I reported there was a massive batch of sites moved to mobile-first indexing in the past several hours. John said that this was the “last batch!”

Not all sites moved. John added that there will still be a “tiny handful of sites that really don’t work on mobile are left.” Those remaining sites, he said, will “just be crawled with desktop Googlebot going forward.”

Notifications. Today, a number of SEOs noticed that sites that have been on desktop-first indexing were notified they were moved to mobile-first indexing. Here is a screenshot from Richard Hearne he posted on Twitter:

History. As a reminder, Google started mobile-first indexing over 6.5 years ago, and eventually, after publishing deadline after deadline, Google removed the deadline. Google first introduced mobile-first indexing back in November 2016, and by December 2018, half of all sites in Google’s search results were from mobile-first indexing. Mobile-first indexing simply means that Google will crawl your site from the eyes of a mobile browser and use that mobile version for indexing and ranking.

Google in early March 2020, before all the lockdowns began across most of the world, announced the deadline for all sites to switch over to mobile-first indexing would be September 2020. At that time, Google said, “To simplify, we’ll be switching to mobile-first indexing for all websites starting September 2020.”  Then in July 2020, Google moved that deadline once again to March 2021.

Why we care. So if your site has not yet been moved to mobile-first indexing, then it might never move to mobile-first indexing. Oh, all new sites by default, should be indexed over mobile-first indexing. The issue is, John said, sites that were not moved over “don’t work with mobile user-agents at all.”

This took a lot longer than anyone expected, but the process seems to be officially now done.