In a recent post, we talked about how mobile banking apps were approaching market saturation; it’s important to recognize milestones like these as indicators of the average user becoming increasingly comfortable trusting their phones to be the hubs of their digital lives.

Another noteworthy breadcrumb in this direction was dropped this week: As of this Monday, Google is finally switching to a mobile-first index. This change might have significant SEO implications if your website isn’t mobile-optimized.

Some context: Google’s crawler bot, Googlebot, crawls the web every day looking at what content is on the web, how it’s presented, who’s linking to who… all to make sure it can surface the best, most relevant results for any given search. But until now, it’s only done this by looking at the desktop version of a site.

That was fine 10 years ago, but in 2015 Google realized "more Google searches take place on mobile devices than on computers”. Mobile-first indexing is Google saying that, when it can, it will crawl and index the mobile version of a site instead of the desktop version. The goal is to ensure that the majority of searchers are seeing search results that actually match up with the content they’ll see on their phones.

So what do I have to do?

If your primary content and markup is different between your mobile and desktop sites, Google’s solution is the obvious one—make sure any content you want to surface in search is added and optimized on your mobile site. If you are already using either a responsive or dynamic serving website (i.e. the source content for both desktop and mobile are presented similarly), you shouldn’t even notice a difference.

If you only have a desktop site? Don’t worry about it… for now. This is mobile-first, not mobile-only. Google will continue to crawl your site like normal. The tide here is clear, however, and those with no mobile web strategy should take note of the direction the search giant (and the market it both creates and responds to) is moving.

But what about my rankings!? Is this “MOBILEGEDDON?”

The short answer is “no.” The update webmasters referred to as “mobilegeddon” was almost three years ago. That was when Google began official prioritizing “mobile-friendly" sites on mobile search, regardless of where the content had been indexed. If you aren’t sure how your site measures up, definitely check out Google’s Mobile-Friendly measurement tool. Google engineers have stated they anticipate mobile-first indexing will have a very minimal impact on search rankings.

As long as you ensure that your key content is available on mobile as well as desktop, and crawlable by the smartphone Googlebot, you should be good to go. This is also still a gradual rollout, and you’ll get a notification in your Google Search Console when your site has made the switch.

This is more of a philosophical change on Google’s part than anything else; as we as humans become increasingly comfortable with a mobile-first approach to our engagement with the digital world, that ecosystem will need to respond in kind to stay relevant. It’s important to take the long view on decisions like this—Google certainly is.