Over 55% of web traffic comes from a mobile device - and counting. It's not then surprising that Google has decided to look at mobile websites first when it comes to search engine indexing. That's why in the not too distant future (and likely this year) Google will be rolling out mobile-first indexing.

What is mobile-first indexing?

Mobile-first indexing will see Google looking at the mobile version of a website when indexing (collecting information per website for use within the Google search engine) and determining ranking signals. If a website doesn't have a mobile version, the desktop version will be indexed instead (hence the 'first' part of 'mobile-first'). If a mobile site hasn’t been provided and the desktop version is used, this could end up being a significant disadvantage when rankings are being determined.

Basically, from the moment the update commences, the mobile version of a website will be considered the primary version; up until now it was the desktop version that was considered the primary version, and the mobile site an alternative version.

If a mobile site is identical and equally as optimised as a desktop site, with full content, structured data markup, backlinks etc (as many mobile responsive design sites will be), then in theory there shouldn't be any difference when it comes to determining rankings.

How will it affect ecommerce in 2018?

How many mobile sites out there really are just as good as their desktop counterparts? Traditionally mobile sites have been a content-light afterthought. That might have to change for the majority of ecommerce businesses; mobile websites around the globe are set to become the priority.

If a merchant wishes to retain or indeed improve rankings in the Google search engine it will be a necessity to ensure that the mobile version of the site is as near to perfect, and generally better than the desktop version. The advantage to the consumer will be an increased mobile experience across the board.

When is moble-first indexing going to commence?

“We don’t have a timeline for the launch yet,” said Gary Illyes at SMX Advanced conference in Seattle last year. “We have some ideas for when this will launch, but it’s probably many quarters away. Our engineers’ timeline was initially end of 2017. Right now, we think more 2018.”

So although there has been no official confirmation on date, it looks like 2018 is the year. What we don't know exactly, is when.

Google said in its Webmaster Central Blog 'Getting your site ready for mobile-first indexing', December 2017: “We will be evaluating sites independently on their readiness for mobile-first indexing based on the above criteria and transitioning them when ready. This process has already started for a handful of sites and is closely being monitored by the search team. We continue to be cautious with rolling out mobile-first indexing. We believe taking this slowly will help webmasters get their sites ready for mobile users, and because of that, we currently don't have a timeline for when it's going to be completed.”

So caution appears to be the name of the game before pushing the button, no doubt coming as a relief to many.

Where should I start and what can I do?

There are a few things you can do quickly to ready your website: Google's Mobile-Friendly test - This tool tests how easily a visitor can use your page on a mobile device. Just enter the page URL to see how it scores. It's an easy and incredibly useful way to find out what Google thinks of your mobile site.


Separate mobile sites – If you have a separate mobile site (rather than a responsive design) you need to ensure all content, structured data, Metadata, XML and sitemaps are the same as your desktop site and fully up-to-date. You should also verify the mobile version with Google Search Console verification.

Google Search Console - Check 'Search Traffic > Mobile Usability' in Google Search Console for any pages on your site with mobile usability issues.


Large files/images - More people using mobile devices also means more people using mobile data. Make sure all large files on site are compressed as necessary. Scalable Vector Graphics (SVGs) are also a great way of retaining a consistent, polished look for logos and icons.

Remove the obstacles to a good mobile UX - Make sure adverts and pop-ups work properly on a mobile device, and if you've got any media files that use services not always available on mobile devices make sure they are thoroughly tested so as not to destroy the mobile experience.

content obstacles

Further reading:

How Does Mobile-First Indexing Work, and How Does It Impact SEO? - moz.com

SEO: Preparing for Google’s Mobile-first Index - www.practicalecommerce.com

Mobile-First Indexing: Everything we know, and how it could affect you - searchenginewatch.com