Structured Data
Structured data is machine-readable markup you add to a page's code, usually following the Schema.org vocabulary, to label what a piece of content actually is: a price, an opening time, a rating, an author. Instead of making a crawler infer meaning from running text, you state it directly in a format like JSON-LD. It doesn't change what visitors see; it gives machines an unambiguous, structured version of the same facts.
Why structured data matters
A person reads "7 pm" in context and knows it's an opening time. A crawler, by default, just sees characters. Structured data closes that gap by naming the field: this string is an openingHours value, this one is a price, this one is an author. For classic search, that markup is what unlocks rich results — star ratings, price snippets, FAQ dropdowns. For AI answer engines the case is more modest than it's often made out to be: Google has said directly that no special schema is required for AI Overviews or AI Mode, and structured data isn't a proven independent citation factor on its own. What it reliably does is remove ambiguity, so that if a system does pull from your page, it has less room to get the fact wrong.
How structured data works
In practice you work from a shared vocabulary, Schema.org, which defines types like Product, Recipe, Event or LocalBusiness, each with its own set of properties. The usual implementation is JSON-LD: a small block of code in the page's head or body that's invisible to visitors but parseable by crawlers. For an article, that block might name the author, the publication date and the headline as distinct fields, rather than leaving a parser to guess which line of text is which. The one hard rule is that the marked-up values have to match what's actually visible on the page — Schema.org markup describing a price or rating that isn't shown to visitors is treated as manipulation, not enhancement.
Common mistakes
The most damaging mistake is marking up something that isn't on the page at all — an invented rating, a price nobody sees. That's flagged as deceptive and costs trust with both search engines and AI crawlers. Nearly as common: markup that goes stale, so the JSON-LD still lists last quarter's price while the visible page has moved on. A mismatch between visible content and markup is worse than no markup, because it signals the page can't be trusted for either. Using the wrong type is a subtler version of the same problem — tagging a service as a Product, say — which just confuses whatever's trying to parse it. And treating structured data as a guaranteed ranking or citation lever is its own mistake: it's a clarity aid, not a workaround for thin or unverified content.
Relation to AI recommendations
AI assistants assemble answers from many sources, and among sources that say the same thing, a system generally has an easier time reproducing a fact it can point to cleanly. Structured data doesn't get you cited — Ahrefs' analysis of roughly 75,000 brands found brand mention frequency across the web correlates with AI citation rate far more strongly than backlinks do, and citation selection itself barely overlaps with Google rankings at all. What structured data does is remove interpretation risk once a system has already decided to draw on your page: an opening time or price recorded as a named field is less likely to be misread than the same fact buried in a sentence. Treat it as hygiene that supports accurate reproduction, not as a citation strategy on its own.
Example
Picture a small bike repair shop with its hours, address and reviews written out as normal text on its site. Add LocalBusiness structured data, and the address, phone number, opening hours and average rating become named, machine-readable fields rather than sentences a parser has to interpret. Someone asking an AI assistant "where can I get a bike fixed nearby this evening" gives the system a cleaner shot at reading the hours correctly and naming the shop, instead of guessing from prose and possibly getting it wrong.
Common questions
Do I need structured data if my content is already good?
You still benefit from adding it, but it's not a substitute for the content itself. Good writing is what earns the mention or citation in the first place; structured data just makes the specific facts inside it harder to misread. Google has explicitly said no special markup is required for AI Overviews or AI Mode, so treat it as a clarity layer, not a prerequisite.
Is JSON-LD the same thing as structured data?
No. Structured data is the general concept of machine-readable markup. JSON-LD is one format for implementing it, and the one Google recommends today over older approaches like microdata. The vocabulary it uses — the actual list of types and properties — comes from Schema.org either way.