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What Google’s Mobile-First Index Means for Your Website in 2021

As browsing habits have changed, mobile searches have grown year on year. Today, we don’t have to load the laptop or boot up the desktop to make a purchase, check train times or read the news; rather, we can do it all from our mobile device.

Recognising this shift in search behavior, Google began mobile-first indexing a few years ago. However, it is set to finalise in spring 2021 and moving forward Google will be using the mobile version of your site for indexing and ranking, if it isn’t already. In this blog post, you can find out more about mobile first and what it means for your business:


What Is Google’s Mobile-First Index?

Historically, Google’s ranking systems typically looked at the desktop version of a website’s content to evaluate its usability and relevance, and used this to inform rankings. However, in 2018 Google began mobile-first indexing, meaning for the last three years Google has been primarily using the mobile version of a website to rank it. 

This process has been rolled out slowly over the last few years, and the remaining sites that have not been mobile-first indexed should be by May 2021 according to this video by Google’s John Mueller. Sites that launched after 1st July 2019 were mobile-first indexed by default, it is older sites that Google has been transitioning to mobile-first slowly. 

Simply put, by making sure that your mobile site is performing at its best for usability, speed and overall user experience, you can make the most of the mobile-first index for optimum search visibility, and ultimately, sales.

Despite the prominence of mobile search, some websites are still not mobile-friendly. As such, your site visibility and ultimately online performance could be suffering.


Is My Site At Risk?

Run your website’s URL through Google’s free Mobile-Friendly Test to find out how well your site’s mobile version is performing. You can also use the ‘Mobile Usability’ section in the Google Search Console menu to help identify any non mobile-friendly (mobile unfriendly?) pages you may have on your site. 


Desktop-only Sites, Separate Mobile Subdomains & M-dot URLs

If your website is still desktop-only, make the switch to mobile-responsive as soon as possible, as desktop-only sites will be dropped from Google’s indexing following this update – that includes any and all assets you have on your desktop-only site.

If you have a separate mobile version of your site hosted on a subdomain, it’s likely that you do not have mobile-equivalent pages to desktop – maintaining both a mobile version and a desktop version is resource intensive, and can often lead to different structures and page content.

In 2017, a Deepcrawl study on the top 1 million websites discovered some interesting statistics on why separate mobile sites should be migrated:

  • 21% of separate mobile sites had no canonical to desktop equivalents
  • 18% of mobile sites had canonicals pointing to the wrong page
  • Only 8% of dedicated mobile website have matching title and meta descriptions

….and this is the top 1 million websites! In 2021, we’d like to think that the majority of these websites have since addressed these issues!

M-dot URLs will also be impacted. Google has admitted that there will be m-dot site bugs  they aren’t interested in fixing, including not being able to direct desktop users to the desktop version of the site from search engine results pages (SERPs). Google published a blog post on how to move m-dots over to a responsive website. We recommend using this handy primer to familiarise yourself with the process and understand how migration could benefit your brand.


How Do I Make My Site Mobile-First? 

Google is using its position as king of the web to force webmasters to become more mobile-friendly. However, ultimately it’s about improving user experience and keeping up with how most people now use online search.

If your site could still do with some work to become more mobile responsive, we’ve created a comprehensive checklist to support you in optimising your website for mobile:


1. Mobile And Desktop Equivalent Pages

Whether you have a responsive website, mobile version or dynamic configuration, you need to ensure that you have equivalent pages on desktop and mobile. This includes, but is not limited to:

  • Meta data (title tags and meta descriptions)
  • Internal linking
  • Body content
  • Headings tags (H1, H2, H3 etc.)
  • Structured data

Your content should be accessible and readable on both the mobile and desktop versions of your site. If content or assets aren’t visible on mobile, consider pruning your pages to help improve the usability of your site for mobile. 


2. Mobile Page Speed

With user expectations of mobile page speed growing, Google now considers page speed as a factor in mobile search rankings. To check your page speed for both mobile and desktop, Google has a handy PageSpeed Insights tool which provides a speed score out of 100. The report also includes insights as to why your page speed is X, and what you can do to improve it. 

Google announced last year that from May 2021, Core Web Vitals will become an important ranking factor. Core Web Vitals are elements that directly contribute to your website’s pagespeed, making it more important than ever to prioritise page speed for SEO purposes. 

Aside from benefiting your rankings on SERPs, page speed has been shown to correlate with lower bounce rates, high user engagement and increased conversion rates.


3. Mobile Usability

You need a mobile website that is as user-friendly as possible in order to capture customer attention and leave a positive experience in their mind.

But how do you define mobile usability? Fortunately, the aforementioned Mobile Usability report inside Google Search Console can check whether you have any issues. Some of the more common issues are:

  • Content wider than screen – If the user needs to scroll horizontally in order to see all of the page’s content.
  • Viewport not yet – Your page size should be relative to the user’s screen size. 
  • Small font size – Use font sizes large enough, so users don’t need to zoom in to read your content.
  • Touch elements too close – Clickable elements should be far enough apart that a user doesn’t select the wrong option, as this can be frustrating and off-putting for them
  • Uses incompatible plug-ins – If the page uses out-of-date plug-ins such as Flash. 


It may feel like there are a multitude of changes for you to make to your site. However, there’s no need to panic, simply begin working through this checklist on step at a time. 

If you’d rather someone else take care of this for you, that’s where we come in. Our team of SEO experts can help you make a success of mobile search, including optimum mobile usability, user experience and performance. Get in touch with us today and find out how we can help you to cement your brand and accelerate your sales in the mobile age.