What Is Structured Data?

How structured data works

In general, “structured data” is any data kept in fixed fields, like rows in a spreadsheet or records in a database, as opposed to unstructured content such as the free text of emails, documents, or images. In SEO, the term has a narrower meaning: labels added to a web page that describe what it contains.

Search engines are good at reading text, but they still have to infer what a page is about. Structured data removes some of that guesswork. It pairs each piece of information with a standard label, so a date is marked as a start date, a number is marked as a price, and a name is marked as the business behind the page.

On the web, those labels usually come from Schema.org, a shared vocabulary of content types such as events, products, and businesses. They are most often written as JSON-LD, a small block of code in the page’s HTML that visitors don’t see. The vocabulary, the code formats, and how to write the markup are covered under schema markup.

Why it matters for your business

Structured data helps search engines connect your page to the right facts: who you are, what you offer, where you are, and when something happens. That clarity can support a few goals, though none is guaranteed.

• Rich result eligibility. Google uses certain types of structured data to show enhanced listings, such as product prices and availability, event dates, or recipe details. Markup that is valid and meets Google’s technical requirements and guidelines can make a page eligible. Google still decides whether to show a rich result.
• Clearer signals about your business. Marking up your organization’s name, logo, address, and contact details states those facts in one consistent, machine-readable place. That supports the wider work of entity SEO: helping search engines connect your site with other mentions of your business.
• Machine-readable facts for AI tools. Some marketers add structured data to make key facts easier for AI search tools to read. How each AI system uses markup is not fully public, so treat this as a possible benefit, not a certainty. Google says its AI search features, such as AI Overviews, have no extra technical requirements beyond normal Search eligibility, so markup is not required to appear in them.

Structured data is not a shortcut to higher rankings. It describes content that should already be useful on its own.

Rules to follow and limitations to know

Structured data only works in your favor when it is honest and accurate. A few rules matter most:

• Match the visible page. Mark up only information visitors can actually see on that page. If the page shows one price, the markup should not show another.
• Follow Google’s structured data guidelines. Google publishes general rules plus specific requirements for each rich result type, including which properties are required. Markup that breaks these rules, such as describing content that isn’t on the page, can make a page ineligible for rich results and can lead to a manual action, a penalty applied after a human reviewer at Google finds a problem.
• Keep it current. When prices, hours, dates, or availability change, update the markup at the same time as the page.
• Expect change. The rich result types Google supports, and how they look, change over time. Some types have been limited or retired.

How to get started

1. Check what you already have. Many website platforms and SEO plugins add basic structured data automatically. Look before adding more, so you don’t end up with duplicate or conflicting markup.
2. Start with your most important page types. For many businesses that means organization or local business details on the home or contact page, plus markup for what you sell or publish, such as products, events, or articles.
3. Test before and after publishing. Google’s Rich Results Test shows which Google rich results a page may be eligible for and flags missing required properties. The Schema Markup Validator checks markup against the full Schema.org vocabulary, including types Google doesn’t use for rich results. Valid Schema.org code can still be missing a property Google requires for a rich result.
4. Monitor over time. Google Search Console, Google’s free tool for site owners, has rich result reports that flag errors and warnings for many of the rich result types Google supports, so you can catch problems after site changes.