Matt Jones Matt Jones | 16 May 2018

Well, in late March 2018 Google confirmed that they’d been testing the change and have started the transition. This announcement has unleashed an even bigger tidal wave of content. In this short blog post I’ll cut through the techno-babble and explain the change in simple terms. An ‘idiots guide’ if you will (not that you’re an idiot of course!).

What is the Google Index?

It’s the corpus of web content that Google select from when deciding which web pages to return in their organic search listings for a given search query.

How does data get into the Google Index?

Google send out web crawlers, sometimes  referred to as ‘spiders’ or ‘bots’, to systematically browse the web and identify new URLs. Web crawlers pass URLs to indexing technology which then reads the content and adds it to the index. 

What is a mobile first index?

Until now, Google’s indexing technology has behaved in the same way as a desktop browser i.e. they've been adding content to their index as experienced by those on a desktop computer. 

You’re probably ahead of me at this point... The move to a ‘mobile first’ index marks Google using indexing technology that behaves in the same way as a mobile browser. The content that they’re starting to pull into their index is the content as experienced by visitors on a mobile device.

Why the change?

Simple, Mobile internet use has overtaken desktop and Google want their organic search listings to be based on data that represents content as seen by the majority of their users i.e. as rendered on a mobile device.

Will your rankings be affected?

The killer question!  Your rankings will only change if the content you show to users on a mobile device is different from the content you show to desktop users. Whether this is the case depends on the current design of your website. So, let’s take a look at the most common design approaches and how rankings are likely to be affected for each...

Responsive website - the effect on your rankings will depend

If your websites pages are responsive then they use one template that aims to render the content well on all screen sizes. Whether your rankings will be affected by the move to mobile first indexing depends on whether your pages lose some content when responding to a mobile sized screen. If certain content is not shown to mobile users then a negative effect on rankings is possible.

Dynamic serving website - a negative effect on rankings is likely

If your website is dynamic serving then each page has different template designs for different screen sizes. It is likely that the amount of content shown on a mobile is less than on desktop. Therefore, Google’s indexing technology will index less content and this is likely to have a negative effect on rankings. 

Desktop only website - no change to rankings but they’re already suffering!

If you still only have a site designed for desktop then your site appears tiny on a mobile browser and users have to pinch to zoom in and interact with it. The content does not differ between a desktop and mobile browser so the move to mobile first will not affect rankings. However, you should be aware that your Google rankings on a mobile device will already have been negatively affected by the poor mobile experience that your site delivers i.e your rankings on mobile search will be worse than the rankings a user experienced on desktop search. Considering that over 50% of searches are now performed on mobile devices then its high time you updated to a mobile friendly website!

How are Google rolling it out?

At this stage Google have said that they’re transitioning slowly and “evaluate each site individually on its readiness for mobile first indexing”. However, Google don’t make it clear how they are judging ‘readiness’.

Advice for responsive websites - perform checks

It’s conceivable that if you have a Responsive site design, Google will assume that you’re ready for mobile first indexing and transition your site sooner rather than later. Therefore, as a matter of urgency I would make sure that you’re showing the same content on mobile as on desktop and not dropping certain content on mobile screens.

Advice for Adaptive websites - make changes

Google is not likely to transition your site until they have confidence that your site is ready. To avoid negative ranking changes when the transition happens you will need to revisit your mobile page templates to ensure that they provide the same content, meta data and instructions for bots as your desktop pages.

Advice for desktop only websites - get with the times

This move demonstrates how mobile search has superseded desktop. You need to move with the times and get yourself a mobile friendly site. Mobile visitors to your website will be encountering a terrible user experience and this will already be negatively affecting your rankings and sales.

If you need help assessing the implications of mobile first indexing call for an informal chat with our Head of SEO, Chris Ebbs