Structured data: markup that matches the page

Structured data describes a page in a vocabulary machines can read. Done well it makes a page eligible for richer results. This checklist covers keeping markup accurate, valid and in step with the visible page.

Use it when adding schema.org markup to a template, when rich results disappear, or when a CMS plugin starts generating markup you did not write.

Format and vocabulary

SD-01 Done

Prefer JSON-LD.

Why: Google supports JSON-LD, Microdata and RDFa, and recommends JSON-LD because it sits in one block and is easier to maintain at scale.
Verify: List which formats each template emits. Mixed formats describing the same entity are a common source of duplicates.
Failure mode: A theme emits Microdata and a plugin emits JSON-LD for the same article, with different dates.
Sources: Introduction to structured data markup in Google Search

SD-02 Done

Use the most specific type that fits.

Why: Schema.org types form a hierarchy. A specific type, such as a particular kind of article, says more than a generic one, and Google features are defined against specific types.
Verify: Compare the type used with the feature documentation for the result type you are aiming at.
Failure mode: Every page is marked up as a generic Thing or WebPage, so nothing qualifies for a feature.
Sources: General structured data guidelines; Getting started with schema.org using Microdata

SD-03 Done

Fill in every required property, and the recommended ones you can support.

Why: Each Google feature lists required properties. Missing one makes the item ineligible; recommended properties add detail where the content supports it.
Verify: Validate a sample of real pages, not a hand-made test page, and track errors and warnings in Search Console.
Failure mode: A required field is pulled from a CMS field that is empty on older content.
Sources: General structured data guidelines

Accuracy

SD-04 Done

Mark up only content that visitors can see on the page.

Why: Google requires markup to describe the visible content of the page. Marking up text that is hidden, or that belongs on another page, breaks the guidelines.
Verify: For each marked-up value, find the same value on the rendered page.
Failure mode: An aggregate rating appears in the markup but nowhere on the page.
Sources: General structured data guidelines

SD-05 Done

Keep values current and consistent with the page.

Why: Dates, prices, availability and similar values go stale. Markup that contradicts the page misleads searchers and can be ignored.
Verify: Generate markup from the same data source that renders the visible page, rather than maintaining it separately.
Failure mode: dateModified is hard-coded in a template and never changes.
Sources: General structured data guidelines

SD-06 Done

Treat misleading markup as a real risk.

Why: Markup that misrepresents a page can lead to a manual action, which removes rich result eligibility. Self-serving or fake reviews are a common cause.
Verify: Check the Manual Actions report in Search Console after markup changes.
Failure mode: Review markup is added for reviews the business wrote about itself.
Sources: General structured data guidelines; Spam policies for Google web search

Validation and expectations

SD-07 Done

Validate with both a Google and a schema.org tool.

Why: The Rich Results Test shows which Google features a page is eligible for. The Schema Markup Validator checks the markup against the full schema.org vocabulary, including types Google does not use.
Verify: Run both on one URL from each template after any markup change.
Failure mode: Markup passes the general validator but is not eligible for the intended feature because a Google-required field is missing.
Sources: Introduction to structured data markup in Google Search

SD-08 Done

Leave structured data pages crawlable and indexable.

Why: Google can only use markup on pages it can crawl and index. A noindex or robots.txt block makes the markup irrelevant.
Verify: Run the index-controls checks on the templates that carry the markup.
Failure mode: Markup is added to filtered listing pages that are noindex.
Sources: General structured data guidelines

SD-09 Done

Expect eligibility, not a promise of rich results.

Why: Valid markup makes a page eligible for a rich result. Google decides whether to show one, and it may not even when the markup is correct.
Verify: Measure rich result appearance in Search Console reports over time rather than assuming it from validation.
Failure mode: A launch report counts rich results as delivered because the test tool showed no errors.
Sources: General structured data guidelines; Introduction to structured data markup in Google Search

Worked example

An article marked up from the same data the page shows

<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "TechArticle",
  "headline": "Fixing redirect chains after a platform change",
  "datePublished": "2026-03-02",
  "dateModified": "2026-09-14"
}
</script>

The headline and both dates also appear in the visible page.
TechArticle is more specific than Article for technical how-to content.
Leave out author and publisher properties rather than inventing people or companies that do not exist.

Primary sources for this checklist

These are named rather than linked. Search for the title on the publisher's site to read the current version. Documentation changes, and the source is the authority when it disagrees with this page.

Google Search Central Introduction to structured data markup in Google Search
Google Search Central General structured data guidelines
Schema.org Getting started with schema.org using Microdata
Google Search Central Spam policies for Google web search