JavaScript Object Notation (JSON) is a lightweight, text-based data format for storing and exchanging data. It is human-readable and easy for machines to process.Open glossary entry → is a simple data format that represents information as key-value pairs. It originated from JavaScript but is now used language-independently, especially for data exchange via application programming interfaces (An application programming interface (API) is an interface through which software systems communicate and exchange data. It defines how requests are made and answered.Open glossary entry →).

In the Search Engine Optimization (SEO) covers all measures that help a website become more visible in unpaid (organic) search results.Open glossary entry → context, JSON-LD (JavaScript Object Notation for Linked Data) is a data format for embedding structured data in a page, separate from the visible HTML. Google recommends it where technically possible.Open glossary entry → (JSON for Linked Data) is particularly relevant. It lets you embed Schema markup is code that describes a page's content in a structured way, so search engines understand it not just as text but as clearly classified information.Open glossary entry → directly in a page's HyperText Markup Language (HTML) is the markup language for web pages. It defines the structure and content of a page, such as headings, paragraphs, links and images.Open glossary entry →, for example details about products, articles, reviews or frequently asked questions. Search engines can use this markup to understand content better and sometimes display it as Rich results are enhanced displays in Google, for example with ratings, prices or breadcrumbs, which can be enabled by suitable structured data.Open glossary entry →.

Important in practice:

  • JSON-LD should ideally be output server-side in the HTML,
  • structured data injected only client-side via JavaScript or a tag manager is captured less reliably.

Compared to Extensible Markup Language (XML) is a flexible text format for storing and exchanging data in a structured way. In the SEO context, the XML sitemap is best known.Open glossary entry →, JSON is more compact and easier to handle for many web applications.