Glossary
JSON-LD
JSON-LD (JSON for Linked Data) is the recommended format for adding schema.org structured data to web pages. It's a JSON object inside a `<script type='application/ld+json'>` tag.
JSON-LD is one of three formats for embedding structured data in HTML — the others are Microdata and RDFa. Google's strong preference (and the modern standard) is JSON-LD because it's separate from the visible HTML (no markup interleaving), easier to maintain, and easier to generate programmatically.
Anatomy of a JSON-LD block: `<script type='application/ld+json'>{ ... }</script>`. The JSON inside has at minimum `@context: 'https://schema.org'` and `@type: 'XXX'` (Article, Product, Organization, FAQPage, etc.). Everything else is type-specific properties.
Where to put JSON-LD: in the `<head>` or `<body>`. Google parses both equally. For frameworks (Next.js, Astro, Nuxt) it's typically rendered server-side in the page head. Validate the output at search.google.com/test/rich-results — invalid JSON-LD is silently ignored, so a single typo can break your schema without any visible error.
Common schema types that get rich results: Article (publication date + author bylines in news/blog SERPs), FAQPage (accordion in SERP), HowTo (step-by-step in SERP — though usage is restricted by 2024 guidelines), Product (price + rating in SERP), Recipe (recipe card in SERP), Event (event details + dates). Service, Organization, WebSite, BreadcrumbList don't trigger visible rich results but feed Google's entity graph (Knowledge Panel data).
JSON-LD is also increasingly used by LLM search (ChatGPT, Perplexity, Claude). LLM crawlers parse structured data preferentially when summarizing pages — a page with rich JSON-LD gets more accurate citations and is more likely to be quoted directly.
Example
An AI website builder pricing page includes JSON-LD with `@type: 'Product'` + `offers` array of `Offer` objects + `aggregateRating` (only when reviews are real). Google renders the pricing rich result in SERP (star rating + price + 'In stock'), increasing CTR by ~30% over the same page without JSON-LD.