Google gets all the information it needs about a page from the page itself, and rarely learns anything unique from structured data, says John Mueller
The reason for that is Google only reads the structured data it supports in search results. It’s not a case of site owners not being able to provide additional information with structured data, it’s that Google won’t read it.
Mueller discusses this subject during the SEO office-hours live stream held on December 4.
A site owner submits a question for Mueller asking if there’s any benefit to using structured data markup which is not mentioned in Google’s official documentation.
“Can additional properties in schema, which are not mentioned in Google documentation, give any benefits? Especially in the case of AMP and non-AMP article schema. If we add AMP article properties on non-AMP pages is there any harm or benefit?”
Google’s structured data documentation can be seen here, and includes and extensive number of markup types under the “Feature guides” section.
All markup types correspond to a rich feature in Google’s search results such as FAQs, Q&As, How-to’s, Recipes, and many others. But there are vastly more types of structured data available for site owners to use.
The full list of schema.org structured data types is expansive in comparison to the types of markup supported in Google’s search results.
So the question being asked of Mueller is about the impact of using structured data not supported in Google.
Can unsupported structured data hurt or help a site? Does Google do anything with it at all? Here’s what Mueller says.
Mueller Discusses Unsupported Structured Data
Mueller says there’s no benefit to using unsupported structured data, at least as far as search rankings are concerned.
Although there’s no harm in using unsupported markup either, but Mueller recommends focusing on using structured data for the search features you want to be eligible for.
“There is probably no benefit at all and probably also no harm there. In general we recommend using structured data for the elements you want to have visible in the search results. And the ones we have visible are based on the properties that we have documented.”
Google crawls structured data for the purpose of using the information to display rich results in search.
Mueller notes that Google does not crawl structured data to learn more about the page.
All the information Google uses to organize content in search results is taken from visible webpage content. That’s important to point out because unsupported structured data types can be added to a site without rendering any visual elements on the page.
Google won’t do anything with structured data that’s not visible on a page. Mueller goes on to say it’s rare for Google to get any unique information about a site from its structured data.
“So if you add structured data for things we don’t use for visible rich results, then we can crawl those pages normally, we just don’t use that kind of extra information.
It’s fairly rare that you would be able to provide some structured data on a page which gives us unique information that we don’t see from the page itself.”
Mueller specifically addresses AMP markup, which was mentioned in the person’s original question for him.
“In particular the AMP article markup, that’s not something that tells us something different about the page. It’s just a different way of providing metadata for the page in general.
It definitely wouldn’t cause any problems but I don’t think you would see any advantage of doing that.”
See the full question and answer in the video below:
What SEOs and site owners can take away from this is: stick to what matters most when it comes to implementing structured data.
Prioritize adding Google-supported markup types that will make your pages eligible to be displayed as rich results.
It’s worth mentioning unsupported structured data types may eventually be supported by Google. When Google introduces new types of rich results it usually relies on a markup type that wasn’t supported previously.
So adding a variety of structured data, whether it’s supported or not, can be a way of future-proofing your site for Google.
Do be careful not to add structured data where it isn’t appropriate. For example, don’t add how-to markup to an article if the content isn’t a genuine how-to guide.
Using structured data that doesn’t apply to the content it’s being featured on can be seen as an attempt to manipulate search results, which is against Google’s guidelines.
For more on structured data, and how to implement it correctly, see our resources below: