Home / App / How Does Mobile-First Indexing Work, and How Does It Impact SEO

How Does Mobile-First Indexing Work, and How Does It Impact SEO

While Google has always been based on the computer version of the pages, it is now (for some sites) the mobile version that serves as a reference. It is on it that Google’s algorithm is based, so read this file to understand the SEO impact!

  • Why is Google switching to mobile?
  • How to prepare for the mobile-first index?
  • Questions-réponses Mobile First Index

Mobile, a priority for Google

Why is Google moving to the Mobile First Index?

As Google explained in its official announcement November 4, 2016 (and 15/11 in French ), the change was necessary because of the following paradox:

While globally the majority of queries are made on mobile, Google continued to rely on the computer version to judge the pages. Then, if the mobile version was available, and the user was on mobile to do his research, then the mobile page was proposed to him. There were some adaptations, such as the “bonus” for mobile compatibility (lightweight to tell the truth).

The change announced makes more consistent analysis of Google: if most users use Google on mobile, and they are offered mobile pages in results, both rely on its same pages to judge their relevance. Then with adaptations for searches made on computers and tablets.

This is why Google explains that its main index is the one made up of its mobile robot, the secondary index being that retrieved by its desktop robot. Be careful, this does not mean that there are actually 2 indexes! It should be understood that for Google, its index is primarily mobile, and secondary desktop (+ tablet).

Many of us still say “the standard version and the mobile version”, but it’s a mistake! The evolution of uses is such that we must really think mobile first: the mobile IS the standard version, it’s the rest that is not standard …

Precision: everywhere in this article, as in Google’s communication, unless otherwise stated “mobile” means “smartphone”. This does not include tablets, which are closer to computers.

Is Google’s mobile index already in place?

Yes, the mobile-first index (MFI) has been officially in place since 26/03/2018, but for some sites only ( source ). Those managed by the MFI are notified by a message via Google Search Console .

Share the info on Twitter:

It’s official, the mobile-first index is in place at Google, but for some sites only.CLICK TO TWEET

Do you have any questions ? Ask them in the Google Mobile Index Discussion Forum

As a reminder, here is the history of the implementation of the principle “Mobile First Indexing”:

The first official announcement dates from early November 2016. As the impact can be major (for those who have a very light mobile version for example), Google had warned well in advance.

On 20/06/2017, John Mueller (Google) indicated that there would probably be no (single) launch date for the mobile first index ( source ). It should be expected that it applies as and when on certain sites, when Google believes that these sites are “ready”.

On 03/10/2017, John Mueller (Google) said during a hangout that the first tests “live” began in the Google results pages ( source ). We do not know in which cases this new mobile index is applied, nor how much it represents sites or requests. For now, Google is working to develop classification methods to identify which sites have a mobile equivalent of their “fixed” content.

Is the world really mobile?

I went to see statistics provided by Stat Counter on the use of the Internet and here is what I found: actually at the global level, the trend is very clear.

But when we look at a map drawn up for July 2018, we realize that it depends on the geographical areas. In Asia and Africa, the mobile is the majority, but this is not the case of Europe and even America (more for a long time):

Comment s’adapter à l’index mobile-first ?

It all depends on whether your site is mobile compatible, and if so how (there are 3).

For mobile sites via responsive design

In this case, the design automatically adapts to the available width (in pixels). The URL is the same (between the mobile version and the other) and no device type detection is required.

If this is your case, you have nothing to do but check what happens when Google accesses your site. Read ”  To be tested imperatively “.

For mobile sites via dynamic serving

Mobile Compatibility by the Dynamic Serving Method

In this case, the design automatically adapts to the available width (in pixels). The URL is the same (between the mobile version and the other). The only difference with the responsive design is that the content (source code) differs according to the type of device (which must be detected), the idea being to lighten the mobile version.

If this is your case, you have nothing else to do than to check what happens when Google accesses your site.Lisez A test absolutely .

For mobile sites via a URL apart

Mobile Compatibility by Separate URL Method

In this case, 2 sites (or pages) are created: one for the mobile and the other for the rest. There are a lot of things to do for Google to consider mobile compatible, but if it’s OK then it’s as effective (in SEO terms) as the other methods.

If this is your case, take a step back and ask yourself what differs (in terms of content and structured data) between the mobile version and the other. If the mobile version contains less content than the other version, then you seriously risk seeing your SEO traffic decrease, especially on the long tail. Indeed, by removing words or phrases, you reduce your chances of going out in the SERPs on the queries that refer to them …

Do not miss my paragraph A must be tested .

For incompatible mobile sites

In this case, it’s really time to plan a new version of your site, obviously mobile compatible! Because not only you risk to have SEO problems (Google based on the mobile version in priority), but most of all Internet users will not like to go to your site …

Need a reminder?3 methods to be mobile compatible

For desktop sites + AMP version

If you have a desktop site without a mobile version, but with an AMP version , then Google will be based on your desktop version. Google source:

If you have a non-responsive desktop site but the mobile version is powered by AMP , then Google will be based on your AMP version . That said, it must really be rare such a configuration samuraicares.com.

To be tested imperatively by everyone!

Follow these 4 essential tips:

  1. First, run the mobile compatibility test tool to make sure your site is Google compliant. This is to be done on several pages, because it is page by page that Google evaluates.
  2. Then, launch the “Explore as Google” tool in the Search Console interface. Do not forget to configure the robot mobile version (it is still not selected by default … like what Google is not up to date). I advise you to take the opportunity to request a display, you will see the rendering of your page according to Google. It is on this version that Google will now rely to estimate the quality of your site. Suffice to say that it is imperative that everything is OK! By the way, make sure you  do not block Google’s access to resources needed for mobile rendering ( CSS , JS , images).
  3. It’s good to test on 1 page, but do it on the whole site! Even if your site is responsive design, I strongly advise you to do 2 audits of your site (1 with Googlebot for Smartphones and 1 with Googlebot for Desktop) and compare the results. You can do it for example with my RM Tech tool .
  4. Finally, test your structured data on your mobile version. If (oddly) you only have non-mobile version, then it will become a problem. And if you have nowhere structured data, it is that you have a metro late … Review the Google article and you will see that they talk about it several times, like what is important.
For an audit of structured data in your pages Contact me here

Questions-réponses Mobile First Index

How to know if his site is managed by the mobile-first index?

Officially, you will receive a message of this type in your Google Search Console account (which must be created):


Unofficially, you can study your logs to see if Googlebot smartphone is the main robotthat crawl your pages.

What is the impact of the mobile index for AMP pages ?

AMP- formatted pages are viewed as other mobile pages and the mobile-first index does not change anything for AMP .

If you do not know yet,discover the AMP format

Should we invert rel = alternate and rel = canonical?

In the case of a mobile version on a separate URL, why Google continues to ask to indicate the desktop URL as canonical, and the mobile URL as “alternative”? It would seem logical that it is now reversed. The question was put to Gary Illyes who answered that if Google asked people to reverse that in their pages, it would take “tens of years”!

Does this mean that Google relies on less content?

Since the mobile version sometimes has / often has less content than the computer version, the question makes sense. Gary answered clearly “yes”, Google will rely on mobile content, so depending on the case on less content than the computer version. If this is your case, you may have a fall in Google visibility, at least on the long tail (on queries that require all your content to go out in the SERP ).

His answer :

Will Google ignore hidden content on mobile?

Here, it is not content absent (source code) of the mobile page, but hidden for reasons of mobile ergonomics (UX), for example in the form of accordion. Google has already indicated that it takes less account hidden content by default when the user arrives.

Gary did not answer the question clearly: “We are working on this, there is clearly something to be done about it”.

But later, he made another answer:

“In the mobile-first world, hidden content (on mobile) for user experience reasons (UX) is fully taken into account by Google”

Mobile site on separate URLs or responsive design?

All other things being equal, does choosing a mobile site on separate URLs have a disadvantage compared to a responsive design site? Official answer: no. But in my opinion, it’s still more complicated to manage for SEO (to have a separate mobile site).

With responsive design, should something be checked?

Admittedly, with the responsive design technique, you do not have a priori to worry about this change of Google. But concretely, Gary still recommends to check in Search Console. If I understand his answer, he means that you have to use the “Explore as Google” function, taking care to choose the mobile version (smartphone) of the robot Googlebot.

Will a desktop site only disappear from Google?

Not at all. You just have to understand that it’s the Google mobile robot that will crawl it, but it will always be able to interpret it. We can imagine that the frequency of crawl will be perhaps less, but it is only a supposition.

How will computer results be “calculated”?

Gary confirmed that computer results will be determined from mobile content and criteria.

Will the computer version have no impact?

According to Gary, it’s “too early to be definitive, but the computer version will have less value in this mobile-first world. How much, I can not say it yet. ”

Ask your questions here in the comments or forum ( Google Mobile-First Index ).

About admin

Leave a Reply

Your email address will not be published. Required fields are marked *