Schema markup describes what a page is about in a format search engines parse directly, rather than inferring from the text. It does not improve rankings on its own. What it does is make a page eligible for richer presentation in the results, and eligibility is worth having.
What it can and cannot do
- It can make you eligible for review stars, prices, availability, breadcrumbs, FAQs and similar enhancements.
- It can clarify entities and relationships that plain text leaves ambiguous.
- It cannot move a page up the results by itself.
- It cannot compensate for a page that does not answer the query.
- It will not guarantee any enhancement appears. Eligibility is not entitlement.
Treating schema as a ranking tactic leads to over-marking pages and then to penalties for describing content that is not there. Treating it as accurate description of real content is both safer and more effective.
Getting it right
Three principles cover most implementations.
- Mark up what is actually on the page. Marking up a rating the user cannot see is a guideline violation, not a shortcut.
- Use JSON-LD. It is the recommended format and keeps markup separate from presentation.
- Keep it consistent with the visible content. Prices, availability and ratings in markup should match what the page displays.
Guides in this section
- Breadcrumb schema — reinforcing site structure in the results.
- Service schema — describing services for service businesses.
- Organisation schema — describing the business behind the site.
- Structured data errors — which reported problems are worth fixing and which are not.
Product and local business markup are covered under product schema and local business schema.
When markup causes problems
Invalid markup is usually ignored rather than penalised, so errors tend to mean a missed enhancement rather than damage. The exception is markup that misrepresents the page, which is treated as a manipulation attempt.
Duplicate or conflicting markup is the more common practical issue: a theme, a plugin and a manual implementation each emitting their own version of the same entity produces contradictory descriptions of one page. Where markup is not working, check first whether something else is already emitting it.
For a review of structured data across your site, book an SEO consultation.