Schema Validator

About Schema Validator

This JSON-LD validator checks structured data markup syntax and helps you inspect required Schema.org fields. JSON-LD (JavaScript Object Notation for Linked Data) is the preferred format for adding structured data to web pages, used by Google, Bing, and other search engines for rich results.

JSON-LD Structure Overview

JSON-LD uses a simple structure with context, type, and properties:

Basic JSON-LD Structure:

{
  "@context": "https://schema.org",
  "@type": "EntityType",
  "property1": "value1",
  "property2": "value2",
  "nestedProperty": {
    "@type": "NestedType",
    "nestedValue": "example"
  }
}

Example - Organization Schema:
{
  "@context": "https://schema.org",
  "@type": "Organization",
  "name": "ToolForge",
  "url": "https://toolforge.site",
  "logo": "https://toolforge.site/logo.png",
  "contactPoint": {
    "@type": "ContactPoint",
    "contactType": "customer service",
    "telephone": "+1-555-123-4567"
  }
}

Required Fields by Schema Type

Common Schema Types

Schema.org defines hundreds of types. Most commonly used for SEO:

JSON-LD Validation Algorithm

JavaScript JSON-LD Validation:

function validateJSONLD(input) {
  const report = [];
  const errors = [];
  const warnings = [];

  // Step 1: Parse JSON
  let data;
  try {
    data = JSON.parse(input);
  } catch (e) {
    return { valid: false, error: "Invalid JSON: " + e.message };
  }

  // Step 2: Check required structural fields
  if (!data["@context"]) {
    errors.push("Missing @context field");
  } else if (data["@context"] !== "https://schema.org") {
    warnings.push("Non-standard @context: " + data["@context"]);
  }

  if (!data["@type"]) {
    errors.push("Missing @type field");
  }

  // Step 3: Check type-specific required fields
  const requiredFields = {
    "Organization": ["name", "url"],
    "LocalBusiness": ["name", "address", "telephone"],
    "Article": ["headline", "image", "datePublished"],
    "Product": ["name", "image", "offers"],
    "FAQPage": ["mainEntity"]
  };

  const type = data["@type"];
  if (requiredFields[type]) {
    requiredFields[type].forEach(field => {
      if (!data[field]) {
        errors.push(`Missing required field for ${type}: ${field}`);
      }
    });
  }

  // Step 4: Check common optional fields
  const commonFields = ["name", "description", "image", "url"];
  commonFields.forEach(field => {
    if (!data[field]) {
      warnings.push(`Missing recommended field: ${field}`);
    }
  });

  return {
    valid: errors.length === 0,
    errors,
    warnings,
    data
  };
}

Example JSON-LD Templates

Organization Schema:
{
  "@context": "https://schema.org",
  "@type": "Organization",
  "name": "Company Name",
  "url": "https://example.com",
  "logo": "https://example.com/logo.png",
  "contactPoint": {
    "@type": "ContactPoint",
    "telephone": "+1-800-555-1234",
    "contactType": "customer service"
  }
}

Article/BlogPosting Schema:
{
  "@context": "https://schema.org",
  "@type": "BlogPosting",
  "headline": "Article Title",
  "image": "https://example.com/image.jpg",
  "datePublished": "2024-01-15",
  "dateModified": "2024-01-20",
  "author": {
    "@type": "Person",
    "name": "Author Name"
  },
  "publisher": {
    "@type": "Organization",
    "name": "Publisher Name",
    "logo": {
      "@type": "ImageObject",
      "url": "https://example.com/logo.png"
    }
  }
}

FAQPage Schema:
{
  "@context": "https://schema.org",
  "@type": "FAQPage",
  "mainEntity": [
    {
      "@type": "Question",
      "name": "What is JSON-LD?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "JSON-LD is a lightweight syntax for expressing structured data."
      }
    },
    {
      "@type": "Question",
      "name": "Why use structured data?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Structured data helps search engines understand your content and display rich results."
      }
    }
  ]
}

Product Schema:
{
  "@context": "https://schema.org",
  "@type": "Product",
  "name": "Product Name",
  "image": "https://example.com/product.jpg",
  "description": "Product description",
  "brand": {
    "@type": "Brand",
    "name": "Brand Name"
  },
  "offers": {
    "@type": "Offer",
    "price": "99.99",
    "priceCurrency": "USD",
    "availability": "https://schema.org/InStock"
  },
  "aggregateRating": {
    "@type": "AggregateRating",
    "ratingValue": "4.5",
    "reviewCount": "128"
  }
}

LocalBusiness Schema:
{
  "@context": "https://schema.org",
  "@type": "LocalBusiness",
  "name": "Business Name",
  "address": {
    "@type": "PostalAddress",
    "streetAddress": "123 Main St",
    "addressLocality": "City",
    "addressRegion": "CA",
    "postalCode": "12345",
    "addressCountry": "US"
  },
  "telephone": "+1-555-123-4567",
  "openingHours": "Mo-Fr 09:00-17:00",
  "priceRange": "$$"
}

BreadcrumbList Schema:
{
  "@context": "https://schema.org",
  "@type": "BreadcrumbList",
  "itemListElement": [
    {
      "@type": "ListItem",
      "position": 1,
      "name": "Home",
      "item": "https://example.com"
    },
    {
      "@type": "ListItem",
      "position": 2,
      "name": "Products",
      "item": "https://example.com/products"
    },
    {
      "@type": "ListItem",
      "position": 3,
      "name": "Widget",
      "item": "https://example.com/products/widget"
    }
  ]
}

ISO 8601 Date Format

Schema.org requires dates in ISO 8601 format:

Rich Results Eligibility

Google uses structured data to power rich results in search:

Common JSON-LD Errors

Common Use Cases

• SEO Optimization: Add structured data to improve search visibility and enable rich results
• Content Validation: Verify JSON-LD before deploying to production
• Agency Workflows: Check client markup for completeness and correctness
• Learning Schema.org: Understand required fields for different entity types
• Migration Projects: Validate converted markup from Microdata/RDFa to JSON-LD
• CMS Integration: Test dynamically generated structured data

Limitations

• Syntax validation only: Checks JSON structure and required fields, not semantic correctness
• Limited type coverage: Validates common types; may not cover all 1000+ Schema.org types
• No Google validation: For official rich result testing, use Google's Rich Results Test
• No external references: Doesn't validate URLs or check if referenced resources exist
• No graph validation: Limited support for @graph with multiple entities

Best Practices

• Use JSON-LD format: Preferred by Google over Microdata and RDFa
• Include all required fields: Missing required fields disqualify rich results
• Add recommended fields: More fields provide better context to search engines
• Use full URLs: Always use absolute URLs for image, url properties
• Validate before deploying: Test markup in staging before production
• Monitor in Search Console: Use Google Search Console to track structured data issues