What is structured data (Schema.org)?
Structured data is standardized supplementary information in a page’s source code, usually in JSON-LD format using the Schema.org vocabulary. It describes content such as products, companies, or events in machine-readable form so search engines can understand it unambiguously and sometimes display it prominently.
Structured data: definition and meaning
A page is readable for people, but for machines it is initially just text. Whether “12.90” is a price, a house number, or a time of day is something a crawler has to guess. Structured data removes the guesswork: it states unambiguously what an element is, such as a product, a review, a company, or an appointment.
The shared vocabulary is called Schema.org and was launched in 2011 by several search engine operators, including Google, Microsoft, and Yahoo. For implementation, Google recommends the JSON-LD format: a block of data in the source code that stays independent of the visible layout. AI applications can also evaluate such information, but a guaranteed effect is not assured.
How the markup works
The JSON-LD block describes an entity with fixed properties. A company page, for example, is marked up as “Organization” or “LocalBusiness” with name, address, phone number, and opening hours. The details must match the visible page content. The code is checked with Google’s Rich Results Test or the Schema Markup Validator. Common types for SMEs:
- Organization and LocalBusiness: company data, logo, location, opening hours
- Product and Offer: price, availability, and reviews in an online store
- Article: author plus publication and modification dates for guides
- BreadcrumbList: navigation path in search results
- Event and JobPosting: events and job ads
Real-world example: an online retailer with product data
A retailer of workshop supplies shows prices, stock status, and customer reviews in its store, but Google has to extract this information from the running text. With Product markup that clearly names price, currency, availability, and rating, this information can appear in search results, provided Google chooses to display it.
If the markup is generated automatically from the shop system, it stays up to date and no outdated prices end up in the index. With manual maintenance, exactly that tends to happen quickly: price changes in the shop are forgotten, and visitors see a different price in search than on the page.
Benefits, limitations, and common mistakes
Structured data creates clarity and is a prerequisite for many enhanced displays in search. It is not a ranking bonus, however, and Google decides case by case whether a rich result appears. Google has restricted some formats: the how-to display was discontinued in 2023, and FAQ snippets were heavily restricted the same year and are now shown only rarely. Markup that does not match the visible content can even lead to manual actions.
- Information in the markup that is not visible on the page
- Outdated prices or opening hours because the markup is maintained by hand
- Invented or self-awarded reviews
- Faulty code that was never tested
What companies should look out for
Use markup where it has clear benefits: for company data, products, articles, and navigation. Generate it from the same data as the visible page wherever possible, and test it again after every relaunch. Nano Concepts integrates structured data into websites and online stores and reviews it as part of technical SEO audits.
Frequently asked questions about Structured data (Schema.org)
Schema.org is a vocabulary jointly supported by several search engines that defines types such as Product, Organization, or Event along with their properties. It determines how content is described in machine-readable form, regardless of the format in which the code is embedded.
Both describe content according to Schema.org. Microdata is embedded directly in the HTML, while JSON-LD sits in a separate block in the source code. Google recommends JSON-LD because it is easier to maintain and to generate automatically.
Not directly. It helps search engines understand content correctly and can enable rich results that bring more clicks. It does not come with a ranking bonus. Whether an enhanced display appears is decided by Google case by case.
With Google’s Rich Results Test for supported rich results and with the Schema Markup Validator for general Schema.org markup. In Search Console, reports on enhanced displays show which pages have errors or warnings.
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