Google will only index all sites based on mobile websites from the end of March 2021, instead of September 2020. The company wants to give administrators more time to adapt their site to mobile-first indexing.
The search engine has been experimenting with primary indexing based on mobile websites for some time, new and popular websites are already being indexed with mobile-first. Last March, Google announced it would switch to mobile-first indexing for all the websites it indexes by September. Google now says to shift that deadline to March 2021, because administrators ‘cannot easily focus on the work in those uncertain times as they previously could’.
Sites will still be indexed with the desktop Googlebot later, but the bulk of indexing will go with the mobile variant. Due to the switch to mobile-first indexing, websites that are only made for desktops will be indexed less often. Also, websites where the desktop version shows more than the mobile version will potentially be ranked lower in the search engine. After all, Google will mainly index the mobile website and will then miss the information from the desktop site. Therefore, Google recommends that site administrators make their site available for primary indexing based on mobile websites and provides some tips for that.
For example, administrators are advised to use the same robot meta tags for both mobile and desktop sites. Also, the use of certain lazy-loading practices, such as having to press a button to view additional images, is not recommended. The Googlebot does not click on these buttons, which prevents Google from indexing potentially important images. Using alternative URLs for mobile websites, such as m.xyz.com, is also not recommended because the search engine may get confused. Google recommends the use of responsive web design for new websites.