In today’s Google Webmaster Office Hours, John Mueller said that they plan to send notices to webmasters via Google Search Console, alerting them that they would be likely to suffer issues when the mobile first index takes affect.

While those who use responsive design likely won’t have many or any issues, those with other mobile strategies could find themselves with changes to make in order to ensure their sites are being indexed properly when Google does decide to switch to their mobile first index.

We will inform people when we get closer, when we actually have a date, so there is sufficient time for people to kind of resolve issues that they may need to resolve.

We’ll try to also inform sites where we recognize issues, so if we recognize that maybe your mobile version doesn’t have all of the same content or markup that your desktop version has then we’ll try and let you know about that through Search Console as well, so that you kind of are aware of these issues and kind of have time to resolve them.

This would likely be sites with significantly different or truncated content on the mobile version of the page versus the desktop as well as those who are missing important markup, since many site owners removed markup from the mobile versions of pages in order to reduce page speed.  It would likely also catch those who might be inadvertently blocking the mobile Googlebot, something we have seen with some firewall and site protection services for websites.

He also stressed the fact they want to make sure site owners have sufficient time to prepare and get their sites ready for the mobile first index.  We first heard about it in October, and it is still in the testing phase with no imminent launch planned.

I haven’t heard of anyone receiving a notice related to this, so it could be weeks or months away.  But it sounds as though Google also plans to send these notices well ahead of the switch.

The mobile first index will be a huge change and it is great to see that they are going to be very proactive and alerting site owners who might have issues when it does go live, so that sites won’t be impacted negatively when it does.