Google Determines Mobile Usability Based on The Ability to Render the Page
Google Advises Against Using Separate Mobile URLs
Having separate URLs for the mobile and desktop version of a site adds more complexity for website owners to manage, so Google recommends switching to a responsive setup.
Google Uses the Viewport Tag to Understand the Mobile-friendliness of a Page
The viewport tag is used for scaling a page for devices, and Google will use this tag to understand whether the page is mobile-friendly or not. Google won’t automatically categorise a page as a mobile version if it has a viewport tag.
Implement Redirects From Mobile Pages to Desktop Pages For Desktop Users
If you have a separate m-dot site, Google will usually pick this as the preferred canonical version after mobile-first indexing and the m-dot site will be shown in desktop search results. To avoid negative UX, implement redirects to the desktop version for desktop users.
Mobile-friendly Test Doesn’t Respond to Robots.txt Rules
When Changing a Favicon Ensure All Pages Are Updated to Display the Change
When updating a favicon for mobile search, John recommends ensuring all pages are updated and the favicon is consistent across the site, in order to display a clear signal to Google when they re-crawl the pages.
New Sites Will be on Mobile-first Indexing by Default
Google is now switching to mobile-first indexing by default for new websites.
Favicons Now Appear in Mobile Search Results
Favicons are now shown in mobile search results in Google. They don’t require any changes from webmasters as they are updated automatically.
Resource Loading Errors Within Mobile Friendly Test and GSC Don’t Reflect Indexing Errors