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SEO & Webmaster

Schema Markup Checker and JSON-LD Validator

Validate JSON-LD structured data blocks in HTML.

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  • On your device

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Private on your device

Your information stays on your device and is not uploaded.

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Paste page HTML or raw JSON-LD to find script blocks, validate JSON syntax, and flag missing @context or @type properties.

What does a schema markup checker do? It reads the JSON-LD blocks in your HTML and checks that they parse, that each has @context and @type, and that required fields are present.

Common schema markup errors include invalid JSON (trailing commas, smart quotes), missing @context, wrong @type spelling, missing required properties such as name or acceptedAnswer on FAQ items, and relative URLs where absolute URLs are needed.

After fixing issues here, test important URLs in Google's Rich Results Test to see whether Google can use the markup for rich results.

How to use this tool

1. Paste page HTML or a JSON-LD script block. 2. Run validation to list each block and any errors or warnings. 3. Fix invalid JSON or missing @context/@type before deploying.

Worked example

Broken FAQPage snippet (missing @context): {"@type":"FAQPage","mainEntity":[{"@type":"Question","name":"What is JSON-LD?","acceptedAnswer":{"@type":"Answer","text":"Structured data in a script tag."}}]}. Fixed: add "@context":"https://schema.org" at the top level and use absolute URLs where required.

When to use this

  • Before publishing new JSON-LD on a template or CMS export.
  • When Google Rich Results Test reports errors you need to reproduce locally.
  • After copying schema from a third-party plugin or theme.
  • When training a team on structured data quality gates.

Common examples

  • Homepage Organization + WebSite graph → validate both nodes parse.
  • Blog Article schema → confirm headline, datePublished, and author fields.
  • FAQPage with two questions → each Question needs acceptedAnswer.
  • BreadcrumbList → itemListElement order and absolute item URLs.

Common mistakes

  • Trailing commas or smart quotes in JSON-LD.
  • Missing @context on a standalone block.
  • FAQPage entries without acceptedAnswer text.
  • Using relative URLs where absolute URLs are required.

How it works

Paste HTML or raw JSON-LD to extract structured data blocks and validate JSON syntax, @context, and @type fields for common schema issues.

Limitations

Validation checks JSON-LD syntax and common fields. It does not verify rich-result eligibility with Google.

Privacy and file handling

Your data stays on your device and is not uploaded.

FAQ

Frequently asked questions

How do I check my schema markup?

Paste your page HTML or JSON-LD into the checker and review any errors. For Google rich result eligibility, also test the live URL with Google's Rich Results Test.

What is the difference between a schema validator and the Rich Results Test?

A validator checks that the structured data is well formed. The Rich Results Test checks whether Google can show a rich result for it.

Is my HTML uploaded?

No, checking runs on your device.

Part of these workflows

This tool is one step in a longer job. Jump straight to your step or open the full workflow guide.

Related pages

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