TECHNICAL · SEO GLOSSARY
Structured Data Errors
Structured data errors are validation failures in JSON-LD, Microdata, or RDFa markup where required properties are missing, property values are in the wrong format, or the schema type is incorrectly nested. Google\'s Rich Results Test and Search Console report these errors, and they prevent rich result eligibility.
Definition
Structured data errors fall into two categories: **Errors** (preventing rich result eligibility entirely) and **Warnings** (recommended properties missing, reducing rich result quality). **Common error types by schema**: (1) **Article** — missing `datePublished`, `author.name`, `image`, or `publisher.logo`. Google requires all four for Article rich results; missing any one makes the article ineligible. (2) **FAQPage** — missing `acceptedAnswer.text`, duplicate questions, or questions with empty answers. FAQPage rich results (FAQ dropdowns in SERPs) require valid question-answer pairs. (3) **Product** — missing `offers.price`, `offers.priceCurrency`, or `offers.availability`. Product rich results require price and availability; missing these prevents the price/availability display. (4) **LocalBusiness** — missing `address`, `telephone`, or `openingHours`. (5) **BreadcrumbList** — incorrect `position` numbering, missing `name` or `item` on list elements. (6) **HowTo** — missing `step.text` or empty steps. **Format errors** — property values in incorrect format: `datePublished` in a non-ISO 8601 format, `@type` values not matching the schema.org vocabulary, `url` values that are relative rather than absolute. **Nesting errors** — `FAQPage` nested inside `Article` rather than as a separate schema; `AggregateRating` placed outside the parent `Product` or `LocalBusiness`. **JavaScript rendering gap** — structured data injected via GTM (rather than server-rendered) is invisible to Google\'s first-pass HTML parser, which cannot execute JavaScript. This is a particularly common error source: the markup may be technically valid but unreachable by Googlebot unless rendered. The Rich Results Test and PageSpeed Insights validation both execute JavaScript; the actual Googlebot crawl may not render client-side schema.
Why it matters for SEO
Structured data errors directly eliminate rich result eligibility. Rich results (star ratings, FAQ dropdowns, How-To carousels, recipe cards, job posting enhancements) increase organic CTR by 10–40% for pages that display them. A single missing required property — a common oversight during CMS template updates or theme changes — can silently strip rich results from hundreds or thousands of pages. Structured data auditing is not a one-time activity; any CMS update, theme change, or plugin update can introduce markup errors that are not immediately visible in the CMS editor.
How DeepSEOAnalysis checks this
The audit validates JSON-LD structured data in the server-rendered HTML (the response Google\'s crawler parses) at the property level: checks each required field for every schema type detected, validates property formats (ISO dates, absolute URLs, valid vocabulary terms), and flags JavaScript-rendered schema (detected in the client-rendered DOM but absent in the raw HTML response). Property-level error detail identifies the exact missing or malformed field — not just that an error exists. Corrected markup is provided for common error patterns.
Useful tools and resources
GLOSSARY
Related terms
structured data
Structured Data
Machine-readable annotations added to HTML — usually JSON-LD — that explicitly describe what a page is about to search engines and AI systems.
Read definition →structured data
JSON-LD
JavaScript Object Notation for Linked Data — Google\'s preferred format for adding structured data (Schema.org markup) to web pages via a `<script type="application/ld+json">` block in the HTML head or body, keeping machine-readable data separate from visible content and easier to maintain than Microdata or RDFa.
Read definition →structured data
Rich Results
Enhanced search result formats that Google displays beyond the standard blue link, title, and description — including star ratings, FAQ dropdowns, product panels, recipe cards, How To steps, event dates, and job listings — enabled by valid structured data (JSON-LD schema) in the page\'s server-rendered HTML.
Read definition →structured data
Schema Markup
A shared vocabulary of types and properties from Schema.org used to annotate web content in machine-readable format — enabling search engines to understand what content means, not just what it says, and to generate rich results.
Read definition →structured data
FAQPage Schema
JSON-LD structured data that marks Q&A pairs on a page so search engines and AI systems can display and cite them directly.
Read definition →See how your site scores on Structured Data Errors.
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