Glossary
What is JSON-LD?
JSON-LD (JSON for Linked Data) is a W3C standard format for writing linked data in JSON. On websites it's the most common way to add structured data: a script tag holding a JSON object that uses schema.org types to describe the page. Google recommends it over microdata and RDFa.
Why it's popular
Inline formats such as microdata and RDFa add attributes to HTML elements, which ties markup to layout. JSON-LD sits in one script block, so templates can generate it from data without touching the page design. Google's documentation recommends it.
Key parts
@context: the vocabulary, usuallyhttps://schema.org.@type: what the thing is, such as Organization, Article or DefinedTerm.- Properties: name, description, url, and nested objects like author or offers.
@id: an identifier that lets different blocks refer to the same entity.
Example
{"@context": "https://schema.org",
"@type": "Organization",
"name": "AgentLaunch",
"url": "https://www.agentlaun.ch"}
Several JSON-LD blocks can sit on one page, for example DefinedTerm, BreadcrumbList and FAQPage on a glossary page.
Common mistakes
Markup that contradicts the visible page, missing required properties for rich result types, and invalid JSON (a trailing comma breaks the whole block). Validate with Google's Rich Results Test.
FAQ
Where do I put JSON-LD?
Anywhere in the HTML, usually in the head or at the end of the body.
Can JavaScript add JSON-LD?
Yes, Google can read JSON-LD injected by JavaScript, but server-rendered is more reliable.
Is JSON-LD only for Google?
No. Bing and other systems read schema.org JSON-LD too.
Can one page have several JSON-LD blocks?
Yes. Separate blocks for different types are common and valid.