What Does Mobile–first indexing Mean?
To get our website pages indexed or ranked google mainly uses the mobile version of a site, it used to index desktop version while asses relevance of a search query, As most of the users, are using mobile to explore google search, It uses the mobile version of a page for indexing.
Google said that all current websites “earlier unknown to its search” are to get indexed via mobile-first indexing update which will be starting on July 1st, 2019. Existed pages which are still not yet indexed using the same update will be changed to mobile-first indexing from July 1st, but they will be moved when those are willing to be shifted to mobile-first indexing.
“It just means if our pages are published after July 1st, 2019 or unknown to google by default mobile-first indexing will be enabled”
Google states “70% of the websites in the SERP have already been shifted to mobile-first index”
September 2020 Mobile-first Indexing
Google Said “we will shift to mobile-first indexing for all websites from September 2020.” 70% of the sites have moved over already and you can find whether your site has moved or not on Google Search Console “
Google webmaster twitter handle confirmed the same on March 5th 2020.
Google Sends Notices
If our websites are not moved yet, it sends a notice “Mobile-First Index Issue Detected on Your Website”, If it enables mobile-first index it sends
As google starts mobile-first indexing for all websites from September 2020, Don’t ignore any messages on search console, just read those and take necessary action, and ensure your website doesn’t have issues with mobile-crawler otherwise it will impact on your website indexing and ranking on SERP.