To be clear, none of this is exactly new, but John Mueller of Google took the time to explain how mobile-first indexing works with mobile-first indexing. Most sites have been switched over to mobile-first indexing but if you have not, then here is what you need to know specific to m-dot or separate mobile URLs.
The change with mobile first indexing is that we'll use the mobile version (m-dot) as the version for indexing, instead of the www (desktop) version. For most sites, this change has already happened. If your site is already indexed with mobile, nothing will change.
— 🍌 John 🍌 (@JohnMu) January 18, 2021
Ideally you'd also redirect users by device type: if a desktop user accesses the mobile version, redirect to the desktop URL. If a mobile user accesses the desktop version, redirect to the mobile version.
— 🍌 John 🍌 (@JohnMu) January 18, 2021
Curious about mobile first indexing? Find out more here:https://t.co/HdM34hbMpNhttps://t.co/Fg8IfbZbkb
— 🍌 John 🍌 (@JohnMu) January 18, 2021
That last link tells you everything you need to know.
I am not going to cover this in detail again but use that Google resource if you are worried.
As a reminder, Google is going all in on mobile-first indexing March 2021 after giving us an initial deadline of September 2020. This initiative was first announced in 2016 - so we had plenty of time to prepare.
Forum discussion at Twitter.
