Schema Markup Validator

Paste JSON-LD and get errors explained in plain English — instantly, in your browser.

What this tool does

The Schema Markup Validator checks any JSON-LD structured data for problems and explains them in plain English. Paste a block (with or without its script tag) and it validates the JSON syntax, confirms @context and @type are present and sane, and checks type-specific required and recommended properties for common types like Article, FAQPage, HowTo, Product, and LocalBusiness — separating real errors from nice-to-have warnings.

Invalid structured data fails silently. The page renders normally, nothing looks broken, but search engines quietly ignore the markup — and the rich results it was supposed to earn never appear. The failure modes are mundane: a trailing comma that breaks the JSON, a misspelled property, a FAQPage missing its mainEntity, an Article without a headline. Because nothing visibly breaks, these bugs routinely survive for months on production sites.

Validation runs entirely in your browser — your markup never leaves the page, there's no signup, and you can re-check as fast as you can edit. Fix the errors, consider the warnings, and re-validate. Need markup written from scratch instead? Our Schema Markup Generator builds it from a form.

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