AMP Page Content Should Match Your Normal Pages
AMP pages should consistently match what users would see on normal pages, regardless of a site being moved to mobile-first indexing. It’s OK if some features are missing, but the AMP page content should generally match the content on your normal pages.
Google Will Only Use Content From Mobile Pages if Mobile First
Google will only use the mobile version of content when a site has been moved to mobile first. If your mobile pages have less structured data or images than your desktop pages, Google will not use the content from your desktop site. Google will continue to crawl your desktop pages about 20% of the time to make sure they are not missing any new pages.
Google Recommends a Single Site for Mobile First Indexing
It’s OK to have a separate mobile website for mobile first indexing, provided it’s correctly linked from the desktop version with a mobile rel alternate and a canonical pointing to the desktop page, but Google recommends having a single URL for each piece of content with responsive design or dynamic serving in the future.
Ensure Structured Data Types Used Across Different Page Versions is Consistent
If a site has different structured markup on their desktop and mobile sites, Google would use the schema that is on the version they are currently crawling and indexing. It’s a little different with AMP as certain structured data types are required for some AMP features, so Google also takes this into account. John recommends ensuring the structured data types used across the different versions of a page are consistent.
Speed Testing Tools Don’t Reflect Google’s Ability to Pre-render & Cache AMP Pages
When displaying AMP pages, Google is able to pre-render and cache them directly from the search results, which saves the time typically spent retrieving the initial HTML to get the rendered version. However, this isn’t something that is taken into account in the testing tools.
Testing Tools Will Display Results For Original Page if There is No Redirect to AMP Version
If there is no redirect to the AMP version of a page, Google testing tools will test and display results for the individual regular URL rather than the AMP version, unless you explicitly the test the AMP URL.
Include Structured Markup on Both AMP & Normal Page to Show in SERPs
Structured markup needs to be included on both the AMP and the normal version of a page to be displayed in search e.g. article markup.
Switching to AMP Won’t Provide an Increase to Rankings
Google rank AMP pages the same as they rank other pages, so there is no inherent ranking advantage when using AMP. However, AMP pages are typically faster than HTML pages, which can provide site speed benefits, particularly on mobile. Some search features also require AMP in order to display correctly due to actions such as pre-caching.
Google Determines Mobile Usability Based on The Ability to Render the Page