Validating Structured Data: Syntax, Required Properties and Visible Content
Structured data describes a page in a format machines can read, such as an article's headline, author and publication date. Search engines can use it to understand content and to show enhanced results. It only helps when it is valid, complete for the feature you target and consistent with what visitors actually see.
Choosing a format and placing it
JSON-LD, placed in a script element in the page, is the format Google recommends because it keeps markup separate from the visible HTML. Use vocabulary from schema.org and the types documented for the search feature you want, such as Article, Product or BreadcrumbList.
Generate structured data from the same source as the page content so the two cannot drift apart.
<script type="application/ld+json">
{
"@context": "https://schema.org",
"@type": "Article",
"headline": "Validating Structured Data",
"datePublished": "2026-10-20"
}
</script>Validating syntax and properties
First check that the JSON parses and uses known types and properties; a single missing comma breaks the whole block. Then check feature requirements: each rich result type lists required properties that must be present and recommended properties that improve the result.
Use a rich results testing tool for the feature-level check and a general schema validator for vocabulary errors. Add both checks to the deployment pipeline for templates that carry markup.
Consistency and expectations
Marked-up information must match visible content. Ratings, prices or dates that appear only in markup violate guidelines and can lead to manual actions. Valid markup makes a page eligible for an enhanced result, but search engines decide whether to show it.
Monitor enhancement reports in search consoles after releases, because a template change can silently remove required properties across thousands of pages.