Mobile-first indexing has been enabled?

If you use Google Search Console/GSC, this week you will probably receive an email (or up to four, depending on how many versions of your site you have set up there) saying that mobile-first indexing has been enabled for your site.

First things first, this is nothing to worry about. Google is enabling mobile-first indexing for everyone, not just you. You’re still special for many reasons, but this isn’t one of them, sorry.

So what does this mean?

Basically, instead of using the desktop version of your site as the point of reference for indexing your site, Google will now scan your mobile version first. It’s called mobile-first because it will first try to index the mobile version but default to desktop if a mobile version isn’t available. So, if you don’t have a mobile version of your site (but of course you do) there will be no change.
Most sites on our servers use responsive web design (the design adjusts for screen size), which also means there will be no change, since the mobile version is the same as the desktop version.

If you use AMP or a special mobile theme...

If the mobile version of your website is significantly different from your desktop version, you may encounter some positive or negative swings in traffic. It’s more important than ever to consider your mobile device experience as the primary point of “truth” for the site.
We are seeing Google start to alert people if there is not parity between the AMP and regular site, but no notes so far of issues on other mobile themes or versions. We know that Google is ingesting all this information. We’re just not sure exactly how they are using it.

Why is Google indexing mobile first?

More than 50% of searches happen on mobile, and more and more people are using mobile devices to browse the web. So, it makes sense to switch their index.

What should I do?

There’s no need to take any action at all in response to this email. However, in general terms, it’s worth checking that your site is fast and easy to use on mobile — both because of this change, and to help visitors to your site have a good experience!

Read more: 

Check out Google’s own explanation about  what mobile first indexing is here, and  their announcement about rolling this out here