Schema.org and JSON-LD explained: the structured data Google rewards

Star ratings under a Google result, recipes with cook time, expandable FAQ questions — none of it lives in your visible HTML. Those are rich results, born from structured data: Schema.org-format metadata describing your content in machine-processable language. It's the cheapest-to-implement-well and most-frequently-wasted part of SEO.

What Schema.org really is

Schema.org is an agreed vocabulary (Google, Microsoft, Yahoo, Yandex — 2011) defining entity types and their properties: Article, Product, Recipe, Event, Person, FAQPage... Each type declares expected fields (Article: headline, author, datePublished, image...).

The recommended delivery format is JSON-LD: a <script type="application/ld+json"> block in head or body, independent from visible HTML:

<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "Article",
  "headline": "How HTTP caching works",
  "author": {
    "@type": "Person",
    "name": "Miguel Ángel Colorado"
  },
  "datePublished": "2026-08-27",
  "image": "https://miguelacm.es/og/article.png"
}
</script>

JSON-LD advantages over microdata (attributes scattered through HTML): doesn't pollute markup, survives redesigns, trivially generated programmatically, and Google openly prefers it. Tutorials full of itemscope/itemprop predate current recommendation.

Schemas with real returns

Not every type deserves effort. These produce verifiable rich results today:

Article/BlogPosting: proper attribution on Top Stories and Discover; title, author and dates correctly interpreted.

FAQPage: expandable question accordion directly in results. Brutal for occupying visual space on long-tail searches — exactly our tool pages' format.

HowTo: numbered expandable steps. Perfect for technical guides.

BreadcrumbList: visible breadcrumbs instead of raw URL. Slightly higher CTR plus clear hierarchy.

Product + Offer + AggregateRating: price, stock and stars. Mandatory for serious e-commerce.

Organization/WebSite + SearchAction: knowledge box and search sitelinks.

VideoObject: thumbnail and duration in video results.

Selection rule: implement the schema of content you HAVE, not traffic you dream of. A fabricated FAQPage with questions nobody asks is structured spam — Google applies manual penalties for structured data abuse when it detects tricks.

Nesting: where you win the game

Real power comes composing entities. An article written by a person working at an organization, within a site with a search engine:

{
  "@context": "https://schema.org",
  "@type": "BlogPosting",
  "headline": "Post title",
  "author": {
    "@type": "Person",
    "name": "Miguel Ángel Colorado",
    "url": "https://miguelacm.es"
  },
  "publisher": {
    "@type": "Organization",
    "name": "MiguelACM",
    "logo": { "@type": "ImageObject", "url": ".../logo.png" }
  },
  "mainEntityOfPage": "https://miguelacm.es/blog/post",
  "datePublished": "2026-08-27",
  "dateModified": "2026-08-27"
}

Every nested entity (Person, Organization, ImageObject) is verifiable info reinforcing the Knowledge Graph Google builds about your site. Cross-page coherence (same author with same data) accumulates entity authority.

Validate or don't serve

Two official validators, two uses:

• Rich Results Test (Google): says whether you qualify for specific rich results and shows blocking errors.
• Schema Markup Validator (schema.org): validates full vocabulary, including types without rich results.

Typical errors silently invalidating:

• Wrong date format (ISO 8601 or nothing: 2026-08-27, not 27/08/2026).
• Images out of spec (minimum resolutions per type).
• Invented @type or nonexistent properties for the type.
• Markup for content absent from the visible page (golden rule: only structure what users see).

Automate review after each deploy: our SEO analyzer detects on-page technical issues including structured data, complementing (not replacing) the official Rich Results Test.

Beyond the rich result: why it matters unseen

Even without visible stars, structured data feeds the Knowledge Graph and semantic understanding of your site. In the era of generative AI answers (AI Overviews and successors), well-structured content is what machines cite confidently — structured data is literally the interface between your content and the machines deciding to show it.

FAQ

Do structured data improve rankings? Not a direct ranking factor per Google. Indirectly yes: higher CTR with rich results → more clicks → positive signals. And unambiguous interpretation never hurts when done right.

How many schemas per page? Whatever matches real content: an article carries Article + BreadcrumbList + maybe FAQPage if it has FAQs. Stacking ten irrelevant types dilutes and risks spam flags.

WordPress/plugins? Yoast/Rank Math inject decent basics. For fine control (dynamic FAQs, complex products), generating your own JSON-LD from templates beats any generic plugin.

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