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Google launches mobile-first indexing

by Yao Hu | 28.03.2018

After a year-and-a-half of testing, Google mobile-first indexing has finally begun. Announced earlier this week on webmaster central blog, mobile-first indexing is now the new reality of how Google organises the web.

Commencing on 26th March, Google started migrating websites which follow the best practices for mobile-first indexing. Not every page is already migrated – this is just an initial wave of the huge shift. But it’s certainly the case where mobile-first indexing is rolling out more broadly from now on, and the first targeted batch are those sites already prepared.


What is mobile-first indexing?

To whom may not be familiarised with how Google works, in the past, Google was mainly crawling, indexing and ranking the desktop version of a webpage’s content, which may cause issues for mobile searchers when the desktop version is vastly different from mobile. Given rapidly growing interests in mobile search over the recent decade, Google decided to roll out mobile-first indexing to benefit their mobile users primarily.

Although it was widely called ‘mobile-first index’, to be more accurate, you should always use ‘mobile-first indexing’ when referring to this. The former misused term is often confusing in many cases – Google consistently have one single index algorithm for rendering crawled results and they have never intended to make a separate ‘mobile-first’ index from their ‘main’ index. As explained in the announcement, Google indexed the desktop version of the search result historically, yet increasingly, recently they’re migrating to the mobile version to serve the larger proportion of search queries from portable devices. Google is still pushing mobile-first out to more and more pages, but ultimately, there will only be one indexing working on its own.


What to expect from the mobile-first index?

Mobile-first indexing will prioritise sites which are effectively organised and optimised for mobile. If a webpage has responsive design with their content, or if a webpage serves dynamically with a dedicated mobile version of content, such content will take precedence through mobile-first indexing. Similarly, for sites that have both AMP and non-AMP versions, Google will prefer to index non-AMP mobile page.

(See Google’s developer documentation for more details about how Google determine if the content is mobile).

Wonder if mobile-first is enabled for your site? Webmasters will be notified once their site is migrated to this new version of indexing via Search Console. Also, site owners will be able to see significantly increased crawl rates from the Smartphone Googlebot – crawling data either from Googlebot desktop or smartphone lying in log files will also reveal whether the site has been migrated.


Indexing doesn’t directly affect ranking. Pages being indexed with the mobile-first version indexing won’t have any advantages over desktop content or pages that haven’t been included in the first batch. Having said that, Google continues to encourage mobile-friendly content to be produced. More importantly, since Google is going to be primarily indexing mobile content, more ranking signals will come from the mobile version, such as content richness, consistency, and of course, page speed.


How to stand out?

If your sites already migrated to mobile-first indexing then it’s likely to be said that Google recognises your site following the best practices for mobile. However, rest assured as Google still needs months to fully roll this out, Tug has two tips here to make your site stand out:

  1. Mobile-friendly design

Having mobile-friendly content is always the first option to serve mobile. Apply responsive design to your webpage so it’s able to be interacted with effectively across all variations of devices and browsers. Make sure to follow Google’s best practices for mobile-first indexing and they also provides a handy tool to test out if your page is mobile-friendly.

  1. Verify both versions

It’s fair to say many webmasters are worried about mobile-first indexing if they organise separate mobile version from desktop. As Google will be only looking at the mobile version eventually, it’s wise to verify both versions to make sure the mobile version has consistent and sufficient content compared to the desktop version on page-by-page basis. There’s more room for error, therefore, Google always recommends going with responsive design instead of dynamically serving.