AMP
Accelerated Mobile Pages (AMP) are a stripped HTML version of a page with limited JavaScript functionality, designed to be optimized for speed and cached by Google to preload in search results for an improved user experience. There are several things to keep in mind when utilizing AMP on your site, these are detailed in our Hangout Notes.
Google Requires Rel Alternate to Detect AMP Pages
Google requires a rel alternate to AMP pages to detect the pages, and a rel canonical from the AMP page back to desired canonical page.
Redirect Desktop Users From AMP Pages to Desktop Pages
It’s not a problem to redirect non-mobile users from amp page to its desktop canonical but be careful when redirecting Googlebot desktop.
Mobile-First Index will Support AMP Pages
AMP pages will be used in the mobile-first index if they are set up as separate mobile URLs, or if the AMP page is your canonical page.
Google will Show Normal Version of Page if the AMP Version 404s
The AMP alternate connection will be dropped in event that an AMP page 404s and normal version of page would show instead.
AMP Requires Mobile Rel Alternate to be a Mobile Page
If you want to use an AMP pages as your mobile version, it requires a mobile rel alternate from the desktop pages. The AMP page should already contain a canonical back to the desktop.
AMP Pages Should Include the Full Content of the Equivalent Normal Page
AMP pages with a snippet of content from the normal page would be problematic. They should include the same content on both versions.
Add AMP links to Mobile Pages for Mobile-first
You should add AMP links to your mobile pages.
Primary Content’ Should be the Same on Mobile and Desktop Pages
Google expects the visible Primary content to be the same on mobile and desktop pages, including AMP pages, but the navigation can be different.
Iframes can be added to AMP to add Rating Functionality
If you have AMP pages that show ratings, you can use an iframe to add the rating functionality.
AMP Sites can Also be the Mobile Version
You can reference an AMP site with both mobile rel alternate and rel AMP HTML, however the AMP page will become the primary version when Google moves to mobile-first indexing.