Structured data is information organised in a standard format so search engines, software applications and other systems can understand what a webpage or dataset means.

It can describe three common page details, such as a product price, an article author and an event date. The JSON-LD example in this guide uses 20 September 2026 as its publication date.

For SEO, structured data usually means adding machine-readable markup to HTML with a vocabulary such as Schema.org and a format such as JSON-LD. Google uses this information to better understand page content and determine whether a page is eligible for enhanced search results, known as rich results.

Structured Data at a Glance

Element What it means
Purpose Explains the meaning and relationships within content
Common vocabulary Schema.org
Common format JSON-LD
Other formats Microdata and RDFa
SEO benefit Can make a page eligible for rich results
Ranking impact Does not guarantee higher rankings
Main requirement The markup must accurately describe visible page content

How Does Structured Data Work?

Normal HTML tells a browser how to display content. Structured data adds information about what that content represents and how different pieces relate to one another.

For example, a person can understand this text:

Apple iPhone 16, $799, in stock

Structured data can label each part:

  • "Apple iPhone 16" as a Product
  • "$799" as an Offer price
  • "In stock" as availability
  • The page as a product page

This gives search engines direct information about the relationships between entities. Without that markup, search engines may need to infer those relationships from the page text.

Schema.org provides types and properties for entities such as Product, Organization, Person, Recipe, Event and Article.

What Is Schema.org?

Schema.org is a shared vocabulary for describing entities and their properties on the web.

Schema.org defines:

  • Types, such as Product, Article and LocalBusiness
  • Properties, such as name, author, price and address
  • Relationships, such as an article having an author or a product having an offer

Schema.org supplies the vocabulary. It is not the markup format.

For example:

  • Product is a Schema.org type
  • name is a Schema.org property
  • JSON-LD is the format used to publish that information on a webpage

Google supports many Schema.org types, but Google's documentation determines which types and properties can produce specific Google Search features.

What Is JSON-LD?

JSON-LD is a JSON-based format for publishing linked data.

Website owners commonly place JSON-LD inside a <script type="application/ld+json"> element in the page's HTML. Google generally recommends JSON-LD because it is easier to add and maintain than markup spread across visible HTML.

Here is a simple example describing an article:

<script type="application/ld+json">
{
  "@context": ""@type": "Article",
  "headline": "What Is Structured Data?",
  "author": {
    "@type": "Organization",
    "name": "Example Publishing"
  },
  "datePublished": "2026-09-20",
  "dateModified": "2026-09-20"
}
</script>

The markup should describe information that is visible on the page and accurate. Hidden, misleading or unrelated structured data can make a page ineligible for rich results and may lead to a manual action.

What Are the Main Structured Data Formats?

Format How it works Typical use
JSON-LD Adds a separate JSON block to the HTML The preferred option for most SEO implementations
Microdata Adds attributes directly to HTML elements Older or template-based implementations
RDFa Adds semantic attributes to HTML or other markup Advanced linked-data applications

Google supports JSON-LD, Microdata and RDFa for eligible structured data features. Schema.org documentation explains how its vocabulary works with each format.

What Is Structured Data Used for in SEO?

Structured data can help a page qualify for enhanced search appearances, such as:

  • Product snippets with price, availability and ratings
  • Recipe results with cooking information
  • Article enhancements
  • Breadcrumbs
  • Events
  • Local business information
  • Review snippets
  • Software application details
  • Video results
  • Organisation information

For example, Product structured data can help Google understand product price, availability, shipping details, return policies and review information.

Structured data does not guarantee that Google will display a rich result. Google decides which search features to show based on factors such as the page, query, device, location and search experience.

Correct markup creates eligibility. It does not guarantee a particular search appearance.

Structured Data Versus Unstructured Data

Structured data follows a defined model. Unstructured data does not.

Data type Example
Structured data A database row containing product_name, price and stock_status
Semi-structured data JSON, XML or HTML containing labelled fields
Unstructured data A paragraph, image, video or email without a fixed data model

A webpage can contain all three. Its visible article text may be unstructured, its HTML may be semi-structured, and its JSON-LD may describe the article, author and organisation in a structured way.

How Do You Add Structured Data to a Website?

To add structured data, match the markup to the page, describe visible content and test the result before monitoring it in Search Console.

  1. Identify the page type. Choose a relevant type such as Article, Product, Recipe, Event or Organization.
  2. Use the most specific applicable type. For example, use Restaurant rather than the broader LocalBusiness when appropriate.
  3. Mark up visible, accurate content. The structured data must represent the main content users can see.
  4. Use JSON-LD where possible. It is usually easier to maintain than inline markup.
  5. Include required properties. Each Google Search feature has its own requirements.
  6. Validate the markup. Use Google's Rich Results Test for Google-specific eligibility and the Schema Markup Validator for general Schema.org validation.
  7. Monitor the result. Use Google Search Console reports and URL Inspection after deployment.

What Can Structured Data Not Do?

Structured data cannot:

  • Guarantee higher Google rankings
  • Guarantee a rich result
  • Replace useful, visible page content
  • Make inaccurate information trustworthy
  • Compensate for poor technical SEO or low-quality content
  • Justify marking up content that visitors cannot see

A sound implementation pairs accurate structured data with clear page content, crawlable HTML, relevant internal links and a technically accessible website.

Bottom Line

Use structured data to describe real, visible page content in a format that search engines can process. For most SEO implementations, that means using Schema.org vocabulary with JSON-LD.

The practical value is eligibility and clearer information about entities such as products, articles, businesses and events. Structured data supports search visibility, but it is not a shortcut to rankings.