For some time now Search Engine Land has been sounding the alarm for the impending Mobile-First Index changes Google has been planning to make to their search algorithm. But all indications were that Google wouldn’t be releasing these changes until at least sometime in 2018.
However, Search Engine Land is now reporting that some aspects of the mobile-first index changes have already begun to roll out.
A Mobile-First Index could have some pretty major implications for SEO and web design. Let’s take a look what a Mobile-First Index is, and how you prepare for the impending change.
What does a “Mobile-First Index” mean?
Historically, Google has crawled and indexed the desktop versions of websites for use in their search results. However, as mobile searches increased and eventually overtook desktop searches, Google ran into problems with the quality of its mobile search results. When their search algorithm would return bad mobile search results because they were based on sites that had only good desktop websites, mobile users took notice.

A Temporary “Mobile-Friendly” Solution
Google attempted to correct the issues with their mobile search results by promoting websites with a good mobile experience. They added a “mobile-friendly” label in search results for websites with a good mobile experience. This became known as the “mobile-friendly” update for some, and “mobilegeddon” for others, as the changes both boosted rankings for some sites, and all but destroyed them for others:

The Move to a Mobile-First Index
The folks at Google eventually started experimenting with a Mobile-First Index that crawls and indexes the mobile version of a website for use in its search results. The hope was that this change would produce better search results for both mobile and desktop searchers. However, early tests were problematic, in part because desktop content tends to attract more backlinks than mobile content. Given that backlinks carry a lot of weight in Google’s search algorithm, the test search results weren’t very good.
Google seems to have some of the kinks in their Mobile-First Index worked out. Like many other previous algorithm changes, they’ve begun to roll out their Mobile-First Index very slowly, rather than all at once. That seems like a wise choice for what could possibly be the most major (and disruptive) algorithm change in years.
Be sure to keep an eye on SEO Industry news to see if the ground falls out from under the Mobile-First algorithm change. In the meantime, webmasters should also take steps to ensure that they’re prepared for the eventual full rollout of the algorithm change.
How to Prepare for the Mobile-First Index
If your website isn’t already built with a Responsive Design, then you need a redesign to make it so. You’re also at least 5 years behind the curve. Time to use the money you’ve saved by not redesigning your website for so long to hire a good web developer who can modernize your website.
If your website is already Responsive – great! But there’s still more you need to do. Read on to find out what and why.
Ensure That Mobile Website Assets are Crawlable
Don’t hide your website’s Javascript (.js) and CSS (.css) files from Google’s crawlers. Google needs to crawl these assets to understand your website’s mobile configuration. You can ensure that these assets are crawlable by configuring your robots.txt file. Use Google Search Console to view and test your robots.txt file for compliance.
When Google was using the “mobile-friendly” designation in its search results, websites that mistakenly hid their .js and .css files from crawling didn’t receive that benefit. It stands to reason that a Mobile-First Index could behave similarly. Therefore, it’s probably safest to make sure these files can be crawled by Googlebot.
Test For and Correct Mobile Usability Issues
Monitor your website for Mobile Usability issues with Google Search Console, and correct any that you find:

You can also use Google’s Mobile-Friendly testing tool to dig deeper into any issues mobile visitors may encounter on your site. If you find mobile usability issues with your website, it’s possible that you will be negatively affected by a Mobile-First Index. Work with your webmaster to correct any problems that the tool detects.
Google Search Console also provides a Fetch and Render tool for troubleshooting crawling and indexing issues. Use it to test whether Googlebot can fully crawl and index your website. The tool allows you test both desktop and mobile versions of your website.
Test and Improve Mobile Page Speed
Google has long been focused on making the web faster. Page Speed is still a known organic ranking factor. Check your mobile page speed with Page Speed Insights and correct any issues you find there. But, be aware that the tool doesn’t currently measure speed accurately for websites hosted on NGINX servers (like ours). Check with your webhost if you don’t already know what kind of server your website is hosted on.
Take advantage of the resources above and your website should survive the Mobile-First Index update with minimal impact on organic rankings.
If you’re curious how prepared your website is (or not), feel free to drop us a line to schedule an audit.