Schema markup tells search engines what your content means, not how it looks. Here is which types are worth adding.
Schema markup is code you add to a page to describe what is on it. A human reads “£49” and knows it is a price. A machine sees a string of characters. Schema removes the guesswork by labelling it explicitly as a price, attached to a product, sold by an organisation.
How it works
The vocabulary comes from schema.org, a shared standard backed by Google, Microsoft, Yahoo and Yandex. The preferred format is JSON-LD: a block of structured data in a script tag, separate from the visible HTML, which makes it far easier to maintain than the older inline formats.
Search engines read the block, match it against what is actually on the page, and use it to understand the content. Where the type supports it, they may also show a richer result: star ratings, prices, event dates, recipe times.
The types worth your time
- Organization. Your name, logo, address and social profiles. This is how you establish who you are as an entity, which matters a great deal for AI search.
- Article. Author, publish date, headline. Ties content to a named person, which supports E-E-A-T.
- Product and Offer. Price, availability, reviews. The clearest commercial return of any schema type.
- LocalBusiness. Opening hours, location, phone. Feeds local results.
- BreadcrumbList. Shows the path to the page in the result instead of a raw URL.
- FAQPage. No longer produces a rich result for most sites, but still makes the structure explicit for anything parsing the page.
Where it goes wrong
The common failure is marking up something the page does not show. Review stars in the code with no reviews on the page is a manual action waiting to happen. The rule is simple: schema describes what a visitor can see, it does not add to it.
The other failure is leaving it broken. Schema drifts as templates change, and nothing on the page looks wrong when it does. Validation belongs in your release checklist, which is how we handle it in technical SEO work.
Related reading: our guides to rich snippets and entity-based SEO.
Common questions
Does schema markup improve rankings?
Not directly. Google has said repeatedly that structured data is not a ranking factor. What it does is make you eligible for richer results, which lifts click through rate, and it makes your content easier for machines to interpret correctly.
Which format should I use?
JSON-LD. Google recommends it, it sits in one block rather than being woven through your HTML, and it survives template changes far better than microdata.
How do I test it?
Google’s Rich Results Test shows what you are eligible for. The schema.org validator catches syntax errors the Google tool ignores. Use both, because they check different things.
The short definition is in our glossary entry for schema markup.
