JSON-LD

JSON-LD, JSON for Linking Data, is a way of writing linked data as ordinary JSON: a @context maps the keys to a vocabulary such as schema.org, @type says what kind of thing is described and @id gives it a name. The result is a small graph a machine can read without parsing the page around it.

The format

JSON-LD 1.1 is a W3C Recommendation from July 2020. Every JSON-LD document is valid JSON, so the parsers already on hand read it; underneath, it describes a labeled directed graph compatible with the RDF data model, which is what lets a value in one document point at an entity defined in another. On a web page it travels inside a <script type="application/ld+json"> element. Google recommends it over Microdata and RDFa as the easiest of the three to maintain at scale, accepts it in the head or the body, and reads it when JavaScript injects it after load.

What the audit found inside it

Across 9,483 small-business sites audited by this site in September 2026, with detection covering JSON-LD and microdata, only 17.8% had no schema.org markup at all. The rest mostly carried WebSite, WebPage, BreadcrumbList, SearchAction and ImageObject: the page builder’s description of the website, not the owner’s description of the business. LocalBusiness appeared on roughly a quarter of sites, and a further 13.7% had business schema missing the fields that would make it usable. The format was present; the entity was not. Google’s rule that structured data must describe what the visitor can see applies here too, so the fix is content and markup together. The figures are in what 9,483 small business websites serve to an AI crawler.

Syntax, vocabulary, and the other syntax

JSON-LD is a syntax. Schema.org is a vocabulary, the set of types and properties the @context points at. Microdata is a second syntax for the same vocabulary, written as attributes on the HTML elements themselves. A page can use either syntax for schema.org, and a validator reads both; the choice affects who maintains the markup, not what it means.

A common question

If a site already carries schema markup, why would an audit still call it a gap?

Because the markup usually describes the website rather than the business. Across the 9,483 sites audited, only 17.8% had no schema.org markup at all; most of the rest carried WebSite, WebPage, BreadcrumbList, SearchAction and ImageObject, which the page builder writes on its own. LocalBusiness appeared on roughly a quarter of sites, and a further 13.7% held business schema missing the fields that would make it usable. The syntax was there and the entity was not, so the repair is content and markup together.

Sources

Specification: JSON-LD 1.1, W3C Recommendation. Placement and format guidance: Google Search Central, introduction to structured data markup. The audit figures are this site’s own; sample drawn per metro and trade, percentages describe the sample.