Structured Data
JSON-LD Graph & Duplicate Schema Checker
Most validator only check one JSON-LD block against one schema type lah. But real pages usually got several blocks at the same time — Organization, WebSite, WebPage, Article, plugin output — all linking each other by @id. Paste the whole page HTML and this tool build that reference graph, then catch what per-type validators cannot see: duplicate or conflicting @id, dangling reference that point to nothing, weird circular chain, misspelled @type, and two main entities fighting for the same page.
Runs fully in your browser one. Whatever you paste here never send anywhere except an anonymised usage count.
Paste the whole page source (every <script type="application/ld+json"> block auto extract), or paste raw JSON-LD direct also can.
What this check, and how to fix
Duplicate / conflicting @id. When two nodes share same @id but data different one (different name, logo, or URL), search engine cannot tell which one is real — dunno which value win. Give every entity its own unique @id, or make sure the duplicate really is exact same copy.
Dangling reference. Property like mainEntityOfPage, isPartOf, author or publisher can point to another node just by {"@id":"..."}, no need repeat the data. If that @id never declared anywhere on the page, the reference point to nothing — fix the id, or add back the missing node.
Circular chain. A WebPage pointing to its Article via mainEntity, then Article point back to WebPage via mainEntityOfPage/isPartOf — this one totally normal 2-node pattern (shown here as info only). But a longer, weird loop worth double check lor — usually means copy-paste mistake between plugin blocks.
Misspelled @type. Schema.org type name is case-sensitive PascalCase string. "Aricle" instead of "Article" still valid JSON but not a real type — search engine just quietly ignore it. This tool flag the near-miss spelling against the real schema.org vocab.
Duplicate or competing main entity. A page should generally got one main content entity only — one Article, one Product, one Recipe. Two Article node, or Article and Product not linked together, force search engine to guess what this page actually about.
This one structural / cross-block audit, not a per-type field validator — pair with a dedicated Article, Product, Recipe, Event, FAQ or Local Business schema validator to also check each entity own required properties.