We know Google has said numerous times that content hidden within tabs on mobile is something that Google will index and rank. But John Mueller of Google explained they will not show this content in the search results snippet because users won't see that content by default.
John said this at the 34:55 mark into the webmaster hangout last week. This was highlighted by Glenn Gabe with a great GIF (I like GIFs):
Via @johnmu: For content hidden in tabs on mobile pages (m-first indexing), Google will use that for indexing & ranking, but WILL NOT show that in the snippets in the search results. If G shows it in the snippet, the user should be able to see it on-load: https://t.co/4HwV5iGrYi pic.twitter.com/mOZytwI2JT
— Glenn Gabe (@glenngabe) May 16, 2019
Here is the video embed:
Here is the transcript:
I've been noticing that content in under tabs on the mobile side is not showing the same way in the search results as was promised. What gives Google?
So what generally happens with with content that is hidden behind a tab, is we will use it for indexing, we'll use it for ranking. So that's something from especially with the mobile first indexing, when we index the mobile version of the page, that's not a problem. So it shouldn't affect ranking but what will happen is we won't show it a snippet. In particular the snippet... We try to separate that out because if we show something in the snippet, it feels like we're really promising the user that they'll see this when they visit that page. So if we know that this is hidden by default then we won't show it in the snippet.But from a ranking point of view, it it'll rank normally. So that should be fine.
John also responded to some additional questions about this on Twitter this morning:
I don't know for sure, but my understanding is that it would.
— 🍌 John 🍌 (@JohnMu) May 17, 2019
Glenn's post says it'll be used for ranking.
— 🍌 John 🍌 (@JohnMu) May 17, 2019
Forum discussion at Twitter.