Smartphone on female hands browsing Google Home Page and in background a portable computer with the same site

What you need to know about Google “mobile-first” changes coming in March 2021

Google have confirmed that from March 2021 they will definitely be using ‘mobile-first indexing’ after pushing forward the deadline from September 2020.

This blog post will tell you all the key things you need to know about this change.

What is mobile first indexing?

This is where Google will predominantly use the mobile version for indexing and ranking of content. This is compared to historically where only the desktop versions of content would be used by Google.

Why has Google done this?

The main reason that has been done is because the majority of Google’s users now access search using a mobile device.

What implications will this have on websites now?

The major takeaway from this is that desktop only sites will be dropped completely. This includes images and other assets that are also present on the desktop version.

What are the current issues with ‘M-dot’ sites?

Websites that are not responsive and have versions that are mobile only are called “M-dot’ sites.

The issue here is that M-dot sites use the ‘hreflang attribute”. The result of this is that with the new mobile index, it will cause Google to send desktop users to the mobile version of the website when using a desktop browser.

As March 2021 is Google’s final deadline, the “only solution” according to Google’s John Mueller Is to “redirect users from the m-dot version to the desktop version”.

How to ensure your site is prepared for the new mobile index going forward?

  • Make sure that the primary content on your desktop website is the same as on the mobile version.
  • Be aware of anything that is blocked
  • Any robots meta tags and lazy loading on the mobile version
  • Images and videos – checking image quality, alt attributes, making sure image URLs remain consistent between the desktop and mobile version, video mark-up, image video placement.

You can read about this in more detail in Google’s documentation here

You can also test your current website to check if it is ready for Google’s mobile-first index using this tool made by Google.

What will happen if your website is not correctly prepared for this change?

If your website is not prepared to be indexed by the March 2021 deadline, this mobile-first indexing will be forced on your site.

The impact of this is that there may be harm to the site’s ranking when migrated. This means it is important the site is prepared before the March 2021 deadline and voluntarily migrated by Google, so that this does not occur.

This can mean that website traffic as well as online sales could decrease due to the site appearing lowering in Google search rankings.

How we can help

Here at O’Brien Media, we can ensure that your website is fully prepared for the new Google mobile-first index. Please do not hesitate to get in touch with the team!

Image credit: Stefano Garau –