JSON-LD Validator & Auto-Fixer

DigitalDomainKit's JSON-LD Validator & Auto-Fixer checks pasted structured data for valid JSON syntax, looks for reachable @context and @type markers, and returns a formatted JSON version when parsing succeeds. It accepts raw JSON-LD or a copied <script type="application/ld+json"> block, then reports the result in a simple three-part audit.

The current validator is useful for catching syntax mistakes and confirming that a JSON-LD document has the basic markers expected in Schema.org-style structured data. It is not a complete Schema.org validator, Google Rich Results Test replacement, eligibility checker, or guarantee that search engines will use the markup. Treat it as a fast first pass before reviewing the final deployed page with the official tools for the feature you are targeting.

What the Validator Checks

The inspected implementation submits the textarea value through a Livewire request. Before parsing, it removes opening and closing <script> tags with a regular expression and trims surrounding whitespace. It then calls PHP's json_decode() to check whether the remaining text is valid JSON. If parsing succeeds, the tool formats the decoded data with JSON_PRETTY_PRINT and JSON_UNESCAPED_SLASHES, so URLs remain readable in the output textarea.

After a successful parse, the component walks the decoded value looking for JSON-LD facts. The repaired traversal handles a single root object, a root array of nodes, an @graph array, and nested objects or arrays below properties such as mainEntity, author, publisher, offers, or similar structures. A root or parent @context is treated as inherited by child nodes during this check. The type check passes when at least one reachable JSON-LD node contains @type.

How to Use the JSON-LD Validator

1. Copy the JSON-LD you want to inspect. You can copy only the JSON object or array, or include the surrounding <script type="application/ld+json"> wrapper.
2. Paste it into the field labeled Enter JSON-LD Schema.
3. Click Validate JSON-LD.
4. Review the Validation Results panel for JSON syntax, schema context, and schema type status.
5. If the tool returns formatted JSON or a repair suggestion, review it in the Formatted / Fixed JSON textarea before copying.
6. Use Copy to copy the formatted output, then test the final page HTML with a dedicated structured-data validator before publishing.

The validator does not fetch a URL, crawl a page, render JavaScript, upload a file, or inspect the visible content that the JSON-LD describes. It works with the pasted text only. If your structured data is injected by a tag manager, CMS plugin, theme, or JavaScript bundle, validate the final rendered page separately after deployment or in a staging environment.

Verified Examples

The following examples reflect production behavior reviewed on September 16, 2026. They are small on purpose so the audit result is easy to see.

@graph document with inherited context

This input passes all three rows. The root object has @context, and the graph node contains @type. The context is treated as available to the graph node during traversal.

{
  "@context": "https://schema.org",
  "@graph": [
    {
      "@type": "Organization",
      "name": "Example Co"
    }
  ]
}

Verified result: JSON Syntax passes, Schema Context passes, and Schema Type passes with the message Found @type on a JSON-LD node.

Root array of JSON-LD nodes

This input also passes all three rows. Earlier root-only checks often miss this shape, but the repaired validator now walks list items.

[
  {
    "@context": "https://schema.org",
    "@type": "Article",
    "headline": "Test"
  }
]

Verified result: the syntax, context, and type rows all pass, and the formatted output remains a JSON array rather than being changed into an object.

Nested node using a parent context

This input has @context on the root object and @type on a nested mainEntity. The current traversal passes the context and type checks because context is inherited while nested arrays and objects are inspected.

{
  "@context": "https://schema.org",
  "mainEntity": {
    "@type": "FAQPage",
    "name": "Questions"
  }
}

Verified result: all three rows pass. This confirms the validator can see nested JSON-LD nodes, but it does not confirm that FAQPage is the right type for your page or that your page meets any search-engine documentation.

Missing type

This input has valid JSON syntax and a context, but no reachable @type.

{
  "@context": "https://schema.org",
  "name": "No type"
}

Verified result: JSON Syntax passes, Schema Context passes, and Schema Type fails with No @type found on any JSON-LD node.

Auto-Fix Behavior and Its Limits

The auto-fix label should be read narrowly. When JSON parsing fails, the component tries three simple repairs: converting curly quote characters to straight double quotes, removing trailing commas before closing brackets or braces, and adding quotes around simple unquoted keys that match its basic pattern. If the repaired text parses, the tool formats that result. If the repaired data is an object and lacks a root @context, the fixer adds "@context": "https://schema.org" at the root.

This can help with common copy-and-paste mistakes, but it is not a safe refactoring engine. It does not understand JavaScript comments, broken nesting, invalid string escaping, partial snippets, duplicate keys, mixed HTML, custom contexts, or whether an automatically added Schema.org context is appropriate. Always compare the fixed output with the original intent before using it.

One important display detail: if the input is not parseable JSON, the context and type rows may still show their initialized pass messages while the syntax row fails. In that situation, treat the syntax failure as the meaningful result. The validator cannot reliably inspect @context or @type until the JSON parses.

Validation Limitations

JSON-LD validation has layers. This tool covers the first layer: is the pasted text valid JSON after optional script tag removal, and can the tool find basic JSON-LD markers somewhere in the decoded structure? It does not cover the deeper layers that matter before production publication.

• It does not validate all Schema.org types, properties, ranges, cardinality, or recommended fields.
• It does not check Google's rich result requirements, enhancement eligibility, warnings, or search appearance rules.
• It does not compare structured data against visible page content.
• It does not fetch your canonical URL, rendered DOM, tag-manager output, or CMS template.
• It does not guarantee ranking changes, rich results, error-free Search Console reports, or acceptance by any search engine.
• It does not validate URLs, dates, prices, currencies, ratings, addresses, availability, or identifiers beyond JSON syntax.
• It does not detect every semantic problem, such as a Product schema placed on a category page or an Organization node describing the wrong entity.

For production structured data, use this page as an early cleanup step, then validate the final rendered HTML. A snippet can pass JSON syntax here and still fail a rich-result test because a required property is missing, a value is inconsistent with the visible page, or the selected type is not supported for the search feature you want.

Privacy and Processing Notes

The visible validator flow sends the pasted textarea content to the Digital Domain Kit application through Livewire so the server-side PHP component can parse it. The page does not provide a file picker, URL fetcher, crawl queue, account workspace, or visible saved-history feature for this tool, but pasted content is still transmitted to the site to produce the result. Do not paste confidential client data, unpublished prices, private addresses, embargoed launches, access tokens, or internal identifiers unless your workflow permits server-side processing through this service.

The copy button uses the site's browser clipboard helper on the formatted output. Clipboard permissions, browser security settings, focus state, extensions, and clipboard history can affect what happens after you click it. If copying fails, select the output manually and use your normal keyboard shortcut.

Troubleshooting

Related Tools for Structured Data Work

Use this validator alongside other DigitalDomainKit tools depending on where you are in the structured-data workflow.

• Schema.org JSON-LD Generator creates starter snippets for common structured-data types before you review and validate them.
• Microdata to JSON-LD helps convert older Microdata markup into JSON-LD for inspection.
• JSON-LD to Microdata is useful when a project needs the opposite conversion direction.
• JSON Validator checks generic JSON syntax when the payload is not specifically structured data.
• JSON Beautifier reformats JSON-LD snippets when you only need readability.
• SEO Tags Generator helps draft metadata that often lives near structured data in a page template.
• SERP Simulator helps compare title and description text with the content your structured data describes.

Technical References

• JSON-LD 1.1 specification
• Schema.org JSON-LD examples
• Google Search documentation on structured data
• Google Rich Results Test
• Schema Markup Validator

Editorial Notes

Technical behavior was reviewed on September 16, 2026 against the deployed Livewire component for /tool/json-ld-validator. Production checks confirmed that an @graph document, a root array, and a nested node with inherited context pass the repaired traversal. Additional checks confirmed missing context and missing type failures, script tag stripping, formatted output for valid JSON, a limited trailing-comma repair, and no repair for an incomplete object.

This article intentionally avoids claiming full Schema.org validation, Google rich-result validation, perfect SEO results, complete auto-repair, or search-engine approval. The safest workflow is to use the tool for quick syntax and structure checks, edit the JSON-LD so it accurately describes visible page content, and validate the final rendered page with the specialized tools for your target search feature.