Notes from the Google Webmaster Hangout on the 23rd of August 2019.
Empty or Thin Pages Can be Served if Different Content is Shown Depending on Location
Empty or thin pages may be displayed in Google’s index if different content is served based on the visitor’s location. E.g. if a full content page is served to US visitors but not to non-US visitors, the page might still be indexed as Googlebot crawls from the US but non-US visitors wouldn’t see the content.
URL Removal Tool Hides Pages But Doesn’t Impact Crawling or Indexing
The URL Removal Tool only hides a page from the search results. Nothing is changed with regards to the crawling and indexing of that page.
Either Disallow Pages in Robots.txt or Noindex Not Both
Use Global Identifiers in JSON-LD so Google Can Group Different Versions of Products
Global identifier markup is useful so Google can potentially group together different versions of the same product or different sites selling the same product.
XML Sitemaps Should Include URLs on Same Path Unless Submitted Via Verified Property in GSC
XML sitemaps should contain URLs on the same path. However, URLs in sitemaps submitted via GSC can be for any valid property within your GSC account.
More or Less Every New Website is Rendered When Google Crawls it For the First Time
Nearly every website goes through the two waves of indexing when Google sees it for the first time, meaning it isn’t indexed before it has been rendered.
Google Determines if Pages Need to be Rendered by Comparing Content Found in Initial HTML & Rendered DOM
Google compares the content of the raw HTML of a page from the initial crawl to the rendered DOM after rendering to see if there is new content and to determine if it needs to be rendered going forward.
Google is Rendering More Pages as Cheaper Resource-wise Than Running Rendering Heuristic
Crawling, Rendering & Indexing Will Come Closer Together as Google’s Rendering Capabilities Improve
Martin expects that crawling, rendering and indexing will come closer together as Google improves its rendering capabilities. Google’s engineers are looking into this but there are not yet any timeframes as to when this might happen.