What is JSON-LD?
JSON-LD is a way to embed schema.org structured data in a page as a block of JSON, stating explicitly what the content is about.
Published
Definition
JSON-LD (JavaScript Object Notation for Linked Data) is a way to embed structured data in a page as a self-contained block of JSON, usually inside a <script type="application/ld+json"> tag, using the schema.org vocabulary.
It sits in the HTML but is invisible to the reader. Its only audience is machines.
Why It Matters for AI Visibility
Everything else on a page has to be inferred. JSON-LD is asserted. A model reading your article can guess at the author, the publication date and the subject from the layout, or it can read a declaration that states all three unambiguously — and inference is where attribution errors come from.
It also carries the entity graph. @id and sameAs let you say that the organization on this page is the same organization as the one on your about page and the one on that external profile. Without those links, each mention is a separate unnamed thing.
Example
<script type="application/ld+json">
{
"@context": "https://schema.org",
"@type": "DefinedTerm",
"name": "llms.txt",
"description": "A plain-text file listing a site's key pages for AI systems.",
"inDefinedTermSet": "https://hey-eye.gr/support/"
}
</script>