Structured Data Checker: Detect and Validate JSON-LD Schema Markup
Structured data is how you speak directly to search engines in their own language. While your page content tells humans what your website is about, structured data tells Google, Bing, and other search engines exactly what type of content you have — whether it is a product with a price, an article by a specific author, a FAQ with answers, or a local business with opening hours. When search engines understand your content through structured data, they can display rich results — enhanced search listings with star ratings, prices, FAQ dropdowns, recipe cards, and more — that dramatically increase your visibility and click-through rate.
RankNibbler's structured data checker scans any page for JSON-LD schema markup, identifies the schema types found, and displays the full structured data content so you can verify its accuracy. It is part of the free 30+ point SEO audit — no signup required. Or use the Schema Generator to create structured data from scratch.
What Is Structured Data?
Structured data is a standardised format for providing machine-readable information about a page and classifying its content. It uses the Schema.org vocabulary — a collaborative project between Google, Bing, Yahoo, and Yandex that defines hundreds of content types and properties.
The most widely used format for structured data is JSON-LD (JavaScript Object Notation for Linked Data). JSON-LD is placed inside a <script type="application/ld+json"> tag in your page's <head> section. It is completely invisible to visitors but is read and processed by search engine crawlers.
Here is a simple example of JSON-LD structured data for an article:
<script type="application/ld+json">
{
"@context": "https://schema.org",
"@type": "Article",
"headline": "How to Improve Your Website SEO",
"author": {
"@type": "Person",
"name": "Jane Smith"
},
"datePublished": "2026-03-20",
"dateModified": "2026-03-20",
"description": "A complete guide to improving your website's search engine optimisation.",
"publisher": {
"@type": "Organization",
"name": "RankNibbler"
}
}
</script>
This code tells search engines that the page contains an article, who wrote it, when it was published, and what it is about — information that would be ambiguous from the HTML content alone.
JSON-LD vs Microdata vs RDFa
There are three formats for implementing structured data on web pages. Google recommends JSON-LD and it is the format used by the vast majority of modern websites.
| Format | Implementation | Google Recommendation | Ease of Use |
|---|---|---|---|
| JSON-LD | Separate script block in the head | Recommended | Easy — does not mix with HTML |
| Microdata | HTML attributes on existing elements | Supported | Harder — requires modifying HTML structure |
| RDFa | HTML attributes on existing elements | Supported | Harder — similar to Microdata |
JSON-LD is preferred because it is added as a standalone script block and does not require changes to your existing HTML structure. This makes it easier to implement, maintain, debug, and remove. It is also the format that Google's documentation uses in all examples.
Why Structured Data Matters for SEO
Structured data is worth up to 8 points in the RankNibbler scoring system — one of the highest-weighted checks. Here is why it deserves that weight:
Rich Results in Google Search
The primary benefit of structured data is eligibility for rich results — enhanced search listings that include additional visual elements beyond the standard title, URL, and description. Rich results stand out visually on the search results page and consistently earn higher click-through rates than standard listings.
| Schema Type | Rich Result | Visual Elements | Best For |
|---|---|---|---|
| Article | Top stories carousel, article cards | Image, date, author | Blog posts, news articles |
| Product | Product snippets | Price, availability, star rating, review count | E-commerce product pages |
| FAQPage | FAQ dropdowns | Expandable Q&A directly in search results | FAQ pages, informational content |
| HowTo | Step-by-step display | Steps, images, time estimates | Tutorial and instruction pages |
| Recipe | Recipe cards | Image, cooking time, calories, star rating | Recipe pages |
| LocalBusiness | Knowledge panel, map pack | Address, phone, hours, reviews, map | Local business websites |
| Organization | Knowledge panel | Logo, social profiles, description | Company/brand websites |
| BreadcrumbList | Breadcrumb trail | Hierarchical path in search results | Any page with breadcrumb navigation |
| Event | Event listings | Date, time, location, ticket prices | Event and ticketing pages |
| VideoObject | Video thumbnails | Thumbnail, duration, upload date | Pages with embedded videos |
| Review | Review snippets | Star rating, reviewer name | Review and comparison pages |
| SoftwareApplication | App information | Rating, price, download link | Software and app pages |
Better Understanding of Your Content
Even when structured data does not trigger a visible rich result, it helps search engines understand your content more accurately. This improved understanding can lead to better ranking for relevant queries, as search engines can more confidently match your page to search intent.
AI Overviews and Conversational Search
With the rise of Google AI Overviews and AI-powered search, structured data has become even more important. AI systems consume structured data to generate accurate, attributed summaries. Pages with comprehensive schema markup are more likely to be cited correctly in AI-generated answers because the AI can extract precise, validated information rather than inferring it from unstructured text.
Voice Search Compatibility
Voice assistants (Google Assistant, Alexa, Siri) often pull answers from structured data. FAQ schema, HowTo schema, and LocalBusiness schema are particularly useful for voice search because they provide direct, machine-readable answers to spoken questions.
Essential Schema Types Explained
Article Schema
Use Article schema on blog posts, news articles, and editorial content. It helps Google understand the headline, author, publication date, and featured image. Article schema is a prerequisite for appearing in Google's Top Stories carousel and for article-specific rich results.
Required properties: headline, author, datePublished
Recommended properties: image, dateModified, description, publisher
Product Schema
Product schema is essential for e-commerce SEO. It enables price, availability, and review data to appear directly in search results, making your listing far more compelling than competitors without it.
Required properties: name
Recommended properties: image, description, offers (price, currency, availability), brand, review, aggregateRating
FAQPage Schema
FAQ schema enables expandable question-and-answer dropdowns directly in search results. This dramatically increases the visual space your listing occupies and provides immediate value to searchers. FAQ schema is one of the easiest to implement and among the most impactful for click-through rates.
Required properties: mainEntity (array of Question objects, each with name and acceptedAnswer)
LocalBusiness Schema
For local businesses, LocalBusiness schema (or its more specific subtypes like Restaurant, Dentist, Store) provides your address, phone number, hours, and other business details in a machine-readable format. This data feeds into Google Maps, the local pack, and knowledge panels.
Required properties: name, address
Recommended properties: telephone, openingHoursSpecification, geo (latitude/longitude), url, image, priceRange
Organization Schema
Organization schema helps Google populate knowledge panels with your company's logo, social media profiles, contact information, and description. It should appear on at least your homepage.
Required properties: name, url
Recommended properties: logo, sameAs (social profiles), contactPoint, description
BreadcrumbList Schema
BreadcrumbList schema generates a breadcrumb trail in search results (e.g., "Home > Category > Product") that helps users understand where the page sits within your site hierarchy. It improves CTR by providing navigational context.
Required properties: itemListElement (array of ListItem objects with position, name, item)
HowTo Schema
HowTo schema marks up step-by-step instructions and can display individual steps directly in search results. It is ideal for tutorial content, DIY guides, and process documentation.
Required properties: name, step (array of HowToStep objects)
Recommended properties: totalTime, estimatedCost, tool, supply, image
How to Implement Structured Data
Step 1: Choose the Right Schema Type
Identify what type of content your page contains and select the most specific Schema.org type. A dentist's homepage should use "Dentist" (a subtype of LocalBusiness), not the generic "WebPage". A product review should use "Review", not "Article".
Step 2: Write or Generate the JSON-LD
You can write JSON-LD manually, use a CMS plugin (Yoast, Rank Math for WordPress), or use the RankNibbler Schema Generator which supports FAQ, Article, Product, LocalBusiness, Organization, and Breadcrumb types. Fill in the fields and copy the generated code.
Step 3: Add to Your Page
Place the <script type="application/ld+json"> block in the <head> section of your HTML. Most CMS platforms and SEO plugins handle this automatically.
Step 4: Validate
Test your structured data using Google's Rich Results Test (search.google.com/test/rich-results) to ensure it is valid and eligible for rich results. Then run a RankNibbler audit to verify the checker detects your schema correctly.
Step 5: Monitor
Check the Enhancements reports in Google Search Console to see if Google has found any errors in your structured data and whether your pages are eligible for rich results.
Structured Data Best Practices
- Use JSON-LD format: Google recommends JSON-LD. It is the easiest to implement and the format used in all of Google's documentation examples.
- Only mark up visible content: The structured data should accurately reflect content that users can see on the page. Marking up hidden content or content from other pages violates Google's guidelines.
- Use the most specific type: "Restaurant" is better than "LocalBusiness". "SoftwareApplication" is better than "CreativeWork". Specificity enables more targeted rich results.
- Include all required properties: Each schema type has required and recommended properties. Include all required ones and as many recommended ones as you can accurately provide.
- Keep it accurate: Misleading structured data (fake reviews, incorrect prices, false availability) violates Google's spam policies and can result in manual actions or loss of rich result eligibility.
- Implement on every relevant page: Do not just add structured data to your homepage. Every product page should have Product schema, every blog post should have Article schema, and every FAQ page should have FAQPage schema.
- Test before deploying: Validate with Google's Rich Results Test and the RankNibbler structured data checker before publishing.
Common Structured Data Mistakes
No Structured Data at All
The most common issue is simply having no structured data. Many websites — especially those without SEO plugins — have zero JSON-LD on any page. This means they are invisible to the rich results ecosystem regardless of how good their content is. Adding even basic schema (Article or Organization) is an immediate improvement.
Incorrect or Invalid JSON
JSON-LD must be valid JSON. A missing comma, extra bracket, or unescaped character will cause the entire block to fail silently. Search engines will not display an error — they simply ignore the invalid markup. Always validate with Google's testing tool.
Marking Up Content Not on the Page
Google requires that structured data reflects content visible on the page. Adding Product schema with a price that is not shown on the page, or FAQ schema with questions that do not appear in the visible content, violates guidelines and can result in penalties.
Using the Wrong Schema Type
Using "Article" schema on a product page or "Product" schema on a blog post sends confusing signals. Choose the type that accurately describes the page's primary content.
Missing Required Properties
Each schema type has required properties that must be present for the markup to be valid. Product schema without a name, Article schema without a headline, or FAQPage schema without questions will not generate rich results.
Structured Data for Different Platforms
WordPress
WordPress SEO plugins handle structured data automatically. Yoast SEO adds Article, Organization, and BreadcrumbList schema by default. Rank Math adds even more types including FAQ, HowTo, and Product schema. Both allow customisation through their settings pages. For manual control, use a plugin like "Schema & Structured Data for WP" or add JSON-LD directly to your theme's header.php.
Shopify
Shopify includes basic Product schema on product pages by default, but it often lacks review data and other recommended properties. Use a Shopify SEO app like "JSON-LD for SEO" or "Smart SEO" to add comprehensive structured data including FAQPage, BreadcrumbList, and Organization schema.
Static HTML
For static sites, add JSON-LD manually to each page's <head> section. Use the RankNibbler Schema Generator to create the code for each schema type you need.
How RankNibbler Checks Your Structured Data
The structured data check is worth 8 points in the RankNibbler audit — the joint third-highest weighted check (tied with canonical URL). Here is what the checker evaluates:
Detection
RankNibbler scans every <script type="application/ld+json"> block on the page and extracts the JSON content. If no blocks are found, the page is flagged as missing structured data with a recommendation to add it.
Schema Type Identification
For each JSON-LD block found, RankNibbler identifies the @type property and displays it in the Structured Data tab. This tells you at a glance what types of schema are present on the page.
Full JSON Preview
The tab displays the complete formatted JSON for each schema block so you can visually inspect the properties, values, and structure. This makes it easy to spot missing properties or incorrect values without viewing the page source.
Multiple Schema Support
RankNibbler handles pages with multiple schema blocks — for example, a page might have Organization schema, BreadcrumbList schema, and Article schema all on the same page. Each block is displayed separately with its type clearly labelled.
Structured Data and AI Search
The rise of AI-powered search has made structured data more valuable than ever. Here is how structured data interacts with AI search systems:
- AI Overviews: Google's AI Overviews consume structured data to generate accurate citations and summaries. Product schema helps AI accurately report prices and availability. FAQ schema provides pre-formatted answers that AI can cite directly.
- ChatGPT and Claude: When AI chatbots browse the web, they can parse JSON-LD more reliably than unstructured HTML. Clear structured data increases the chance of accurate representation in AI-generated answers.
- Voice assistants: FAQ and HowTo schema provide the structured Q&A format that voice assistants need to deliver spoken answers to user queries.
Frequently Asked Questions About Structured Data
Is structured data a ranking factor?
Google has stated that structured data is not a direct ranking factor. However, it enables rich results that significantly increase click-through rates, and higher CTR can indirectly improve rankings. More importantly, structured data helps search engines understand your content, which improves your chances of ranking for relevant queries.
How do I check if my page has structured data?
Run a free RankNibbler audit on your URL. The Structured Data tab shows all JSON-LD blocks found on the page, their types, and their content. You can also use Google's Rich Results Test for validation.
What is the best structured data format?
JSON-LD is the format recommended by Google and used by the majority of websites. It is easier to implement and maintain than Microdata or RDFa because it sits in a separate script block rather than being woven into your HTML.
Can structured data hurt my SEO?
Structured data itself cannot hurt your SEO. However, misleading structured data — fake reviews, incorrect prices, marking up content not visible on the page — can result in manual actions from Google that remove your rich results eligibility. Always ensure your structured data accurately reflects your page content.
How many schema types can I have on one page?
You can have multiple schema types on a single page. A blog post page might include Article schema, FAQPage schema, BreadcrumbList schema, and Organization schema all at once. Each type serves a different purpose and they complement rather than conflict with each other.
Do I need structured data on every page?
Ideally, yes. At minimum, every page should have the schema type appropriate to its content (Article for blog posts, Product for product pages, etc.) and your site-wide Organization or WebSite schema. The more pages with accurate structured data, the better search engines understand your entire site.
How do I create structured data without coding?
Use the RankNibbler Schema Generator to create JSON-LD for FAQ, Article, Product, LocalBusiness, Organization, and Breadcrumb types by filling in a simple form. Most CMS platforms (WordPress, Shopify, Squarespace) also have plugins that generate structured data automatically. See our full guide: What Is Structured Data?
How long does it take for rich results to appear?
After adding structured data, Google needs to recrawl your page and process the new markup. This can take anywhere from a few days to several weeks. You can speed up the process by requesting a recrawl in Google Search Console. Note that having valid structured data does not guarantee rich results — Google decides which results to enhance based on quality, relevance, and other factors.
Check Your Structured Data Now
Run a free SEO audit on any URL to check for structured data. The Structured Data tab shows all JSON-LD blocks found, their schema types, and the complete formatted content. If no structured data is found, use the Schema Generator to create it for your page type. For more on structured data implementation, see What Is Structured Data? and How to Create FAQ Schema.