As you may recall, this mobile-first indexing stems from the fact that computing is becoming increasingly more mobile. As always, Google aims to build a great experience on the web for all users, whether they come from mobile or desktop devices.
Mobile-first indexing brings a change in how Google creates and ranks its search listings. Previously Google has crawled the web from a desktop browser point of view in order to decide search results and ranking. The mobile-first index initiative changes this, as Google aims to crawl the web from a mobile browser view and eventually make the mobile version of the web as their primary search engine index. And all of this is because trends are showing that the majority of users are mobile searchers.
Does this mean that mobile content is all that’s going to matter? No, it just means that whatever shows up in Google’s results will be based on the mobile version of content, no matter if users are viewing on desktop or mobile. Desktop content still matters, but mobile content is what is being used by Google. And if there is no mobile site available, Google will just crawl the desktop version instead.
If you have a responsive site already, then you really have nothing to worry about. Responsive design means that content on your desktop site is the same as on your mobile site, perhaps with slight differences in how data is presented.
With Google’s announcement of this initiative happening well over a year ago, one might wonder what’s taking so long. One reason is that Google wants to roll out the mobile-first index in a way that doesn’t hurt non-mobile-friendly sites. There has been plenty of communication and forewarning about the upcoming changes in order that people are not surprised.
Another reason it may be taking so long is the fact that the mobile web contains fewer signals for Google’s ranking system to use than the desktop web. The content and metadata are more scarce on mobile sites than it is on desktop sites. Google doesn’t want mobile-first indexing to mean that there is a loss in quality of search results. Google needs to “replace the signals that are missing in the mobile web” to keep the quality neutral with this upcoming change in indexing.
“We’re still experimenting. We don’t have a timeline. It could be a few months or quarters, but it’s definitely not weeks [away]. Don’t freak out, especially if you have a responsive site.” -Google’s Gary Illyes
Google is going about this with much thought and experimentation, and we shouldn’t expect to see anything until 2018. Use this time of waiting as an opportunity to prepare and make sure all your websites are ready with responsive design.