Schema.org and Google have released a public dataset showing how many sites use each structured data type. Only 12 item types appear on more than 10 million domains. The long tail of useful schema is wide open, which is exactly why the businesses that mark up properly stand out to the machines.
Structured data is how you hand the machines a clean version of your information. Most sites still hand them a mess and wonder why the answers come back wrong.
Schema.org and Google have released something the SEO world has wanted for years. A public dataset showing how many sites actually use each type of structured data. For the first time you can see, in real numbers, which schema types the web has adopted and which barely register.
The first release, dated May 2026, covers 958 item types and 4,587 properties, more than 5,500 entries in total. It is aggregated at the domain level, updated monthly and free on the Schema.org GitHub. A site running a schema type across 500 pages still counts as one domain, so this measures reach across the web, not raw volume.
The shape of adoption is the interesting part. Only 12 item types, the basics like Organization, Person, WebPage and BreadcrumbList, appear on more than 10 million domains. Another 35, including Product, Review, Article, FAQPage and LocalBusiness, sit between 1 million and 10 million. Everything else is rarer than that. The long tail of useful schema is wide open.
Why it matters
Structured data is the closest thing you have to telling AI and search engines exactly what your business is, in language they cannot misread. As more discovery runs through AI answers, that clarity stops being a nice technical extra and becomes the difference between being quoted correctly and being mangled. This dataset shows most of the web has not bothered, which means the businesses that do stand out.
Schema types appear on more than 10 million domains. Everything beyond the basics is wide open territory
The gap is the opportunity. If your competitors are using only the bare minimum schema, the ones who mark up their products, reviews, FAQs and local details properly are feeding the machines a cleaner signal than anyone around them.
What to do about it
The web just got a map of who bothers with structured data and who does not. Most do not. That is exactly why the ones who do are easier for the machines to find, read and trust.