Structured Data Basics for SEO

What structured data is

Structured data is code you add to a page that tells machines what the page is about. It uses a standard vocabulary (schema.org) so different systems can read the same information the same way. A person reads the visible page; a search engine also reads the structured data behind it.

The most common format is JSON-LD, a snippet of JSON embedded in a script tag in the HTML. It sits alongside your visible content and describes it in machine-readable terms.

Why search engines read it

Structured data lets search engines show enhanced results: star ratings, event dates, recipe cooking times, product prices. It also helps them understand what the page is fundamentally about, which is useful when deciding whether to show or quote it.

For AI answer engines, structured data helps with attribution. A page that clearly declares its type (Article, Product, LocalBusiness) and its publisher is easier to cite than one where that information has to be inferred from the HTML.

Common schema types

• Article — Blog posts, news stories, how-to guides. Include headline, author, publisher and publication date.
• Product — Physical or digital products. Include name, image, description, offers and optionally reviews or ratings.
• LocalBusiness — Businesses with a physical location. Include name, address, phone, opening hours and geo coordinates.
• FAQPage — Pages where the primary content is questions and answers. Each question must be visible on the page with its answer.
• Organization — Information about the company or entity behind the site. Include name, logo and URL.
• BreadcrumbList — The navigation path to the current page. Helps search engines understand site structure.

The honesty rule

Structured data must describe what is visible on the page. FAQPage markup for questions that do not appear on the page is spam, not optimization. A Product schema declaring reviews the page does not show is misleading.

Search engines penalize pages whose structured data contradicts or exaggerates the visible content. Use schema to describe what is there, not to invent what is not.

What SEOAST checks

The structured_data check reports whether your JSON-LD parses and which schema types it declares. It does not validate individual properties, because that is what schema validation tools are for. It does check that declared types make sense for the content visible on the page.