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Plaintools

Schema checker

Paste a JSON-LD object, array, or HTML snippet containing schema script tags. The validator inspects @context declarations, @type definitions, and checks recommended and required fields for FAQPage, HowTo, Article, Product, and other Schema.org entities. Runs entirely on your device with no server upload or external API calls.

Local Checks OnlyRuns 100% in your browser · No network calls to Google · Nothing uploaded
Presets:

Paste raw JSON-LD or a <script type='application/ld+json'> snippet.

Schema Syntax & Shape Valid

Found 1 schema node across 1 script block.

0 issues
Article— “How to Build Fast Web Applications
Basic Shape Valid
No structural issues found for this schema type. Required properties and @context declaration are present.

About Plaintools Schema Checker:

This tool performs strict local syntax and structural verification against Schema.org specifications for common rich snippet types (FAQPage, HowTo, Article, Product, LocalBusiness, BreadcrumbList, Organization, Person). It checks required and recommended fields, @context declarations, and sub-object schemas. It is entirely client-side and does not submit URLs or content to Google, Bing, or third-party validation servers.

Example

Article with author and datePublished

An Article schema with headline 'Optimizing Web Performance', datePublished '2026-03-15', and an author Person object validates with 0 errors and generates rich snippet guidance.

Related: Schema markup generator, JSON-LD generator

FAQ

Does this schema checker validate against Google's live Rich Results API?
No. This tool runs 100% locally in your browser. It performs local syntax and structural verification against Schema.org patterns for common types. It does not contact Google or guarantee Google search rich result badges.
Is my structured data or website content uploaded?
No. Everything runs client-side in your browser. No copy, schema markup, or URLs are ever transmitted across the network or stored on any server.
What schema types does this validator check?
It specifically checks structural completeness and recommended fields for FAQPage, HowTo, Article (and BlogPosting/NewsArticle), Product, LocalBusiness, BreadcrumbList, Organization, and Person, while verifying valid JSON-LD syntax, @context, and @type for any Schema.org type.
Can I paste HTML containing <script type="application/ld+json"> tags?
Yes. The validator extracts all <script type="application/ld+json"> blocks from HTML source code automatically and checks each schema block independently.
How do I validate JSON-LD schema without this page?
Parse the JSON string with JSON.parse(). Ensure the root object (or @graph nodes) declares '@context': 'https://schema.org' and a non-empty '@type'. For FAQPage, verify 'mainEntity' is an array of Question objects, each having non-empty 'name' and an 'acceptedAnswer' object with non-empty 'text'. For Article, check 'headline' and 'author'. For Product, check 'name' and 'offers'. For HowTo, check 'name' and 'step' array.