JSON-LD vs Microdata vs RDFa: 3 Powerful Formats for SEO

Structured data helps search engines understand the information on your website. It can describe articles, products, organizations, local businesses, and many other types of content. However, when implementing schema markup, website owners often face one important question: should they use JSON-LD, Microdata, or RDFa?

Understanding JSON-LD vs. Microdata is especially important for SEO professionals who want to implement structured data correctly and maintain it without unnecessary technical complexity.

All three formats can represent structured data, but they work differently. JSON-LD keeps the data separate from the main HTML content, while Microdata and RDFa add attributes directly to HTML elements.

In this guide, we will compare these three structured data formats, explore practical code examples, explain their SEO implications, and show you how to validate or migrate existing schema markup.

What Is Schema Markup and Why Does Format Matter?

Schema markup is structured data added to a webpage to describe its content in a machine-readable format. It helps search engines understand information about articles, products, people, and businesses more accurately.

For example, a blog post might contain a headline, author name, publication date, and description. Schema markup can identify these details so search engines can interpret them more consistently.

Structured data is not a direct guarantee of higher rankings. However, correctly implemented markup can help Google understand eligible content and may make a page eligible for certain enhanced search appearances, depending on Google’s requirements.

The format you choose affects how structured data is added, maintained, and checked.

• JSON-LD: Places structured data in a separate script block.
• Microdata: Adds structured data attributes to existing HTML elements.
• RDFa: Uses HTML attributes to describe relationships and properties.

Google supports all three formats for structured data, but recommends JSON-LD when practical.

JSON-LD vs Microdata vs RDFa: Quick Comparison

Before exploring each format, consider how they differ in implementation and maintenance.

Feature	JSON-LD	Microdata	RDFa
Implementation	Separate JSON script	Attributes in HTML	Attributes in HTML
Readability	Usually easy to read separately	Mixed with page markup	Mixed with page markup
Maintenance	Often easier	Can require HTML changes	Can require HTML changes
Google support	Supported and recommended	Supported	Supported
Best starting point	Most new implementations	Existing Microdata setups	Projects already using RDFa
Complex relationships	Supported	Supported	Supported

The main difference is not that one format can describe information while the others cannot. All three can represent structured data.

The practical difference is how you add that information to your website and how easily your team can manage it.

For most new SEO implementations, JSON-LD is a sensible starting point. Nevertheless, an existing Microdata or RDFa implementation does not automatically need to be replaced if it works correctly and meets your requirements.

What Is JSON-LD?

JSON-LD stands for JavaScript Object Notation for Linked Data. It is a format for expressing structured data using JSON syntax.

Website owners typically add JSON-LD inside a <script type="application/ld+json"> element. This keeps the structured data separate from the visible HTML layout.

Example of JSON-LD schema markup

Imagine you have published a blog post about technical SEO. The following simplified example describes that article:

<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "Article",
  "headline": "A Beginner's Guide to Technical SEO",
  "description": "Learn the basics of technical SEO.",
  "author": {
    "@type": "Person",
    "name": "Alex Smith"
  },
  "datePublished": "2026-10-01"
}
</script>

This example identifies the content as an Article and provides its headline, description, author, and publication date. Replace the sample details with accurate information about the actual page.

Advantages of JSON-LD

1. Easier to maintain

Because the markup is separate from the main HTML content, developers can often update structured data without changing individual content elements.

2. Clear structure

JSON-LD uses familiar key-value pairs and nested objects. This can make it easier to understand relationships between entities, such as an article and its author.

3. Recommended by Google

Google recommends JSON-LD as the preferred structured data format when it is practical to use.

4. Convenient for CMS platforms

Many content management systems and SEO plugins can generate JSON-LD automatically. However, you should check their output rather than assuming every field is correct.

Limitations of JSON-LD

JSON-LD still requires correct syntax and accurate information. Invalid JSON, incorrect property values, or mismatches between the markup and visible page content can cause problems.

It is also possible for a plugin, theme, and manually added code to produce duplicate or conflicting structured data.

JSON-LD is often easier to maintain, but it is not automatically correct simply because it uses the recommended format.

What Is Microdata?

Microdata is a structured data format that adds attributes directly to HTML elements. These attributes identify an item, its type, and its properties.

Three important attributes are:

• itemscope: Defines an item.
• itemtype: Specifies the item’s type.
• itemprop: Identifies a property of that item.

Example of Microdata

The same technical SEO article can be represented using Microdata:

<article itemscope
         itemtype="https://schema.org/Article">

  <h1 itemprop="headline">
    A Beginner's Guide to Technical SEO
  </h1>

  <p itemprop="description">
    Learn the basics of technical SEO.
  </p>

  <div itemprop="author"
       itemscope
       itemtype="https://schema.org/Person">

    <span itemprop="name">Alex Smith</span>

  </div>

  <meta itemprop="datePublished"
        content="2026-10-01">

</article>

Here, the article element defines an Article item. The itemprop attributes identify the headline, description, author, and publication date.

Advantages of Microdata

1. Connects markup to visible content

Microdata associates properties with specific HTML elements, making it easier to see which visible content a property describes.

2. Useful for existing implementations

If your website already uses valid Microdata, you may be able to maintain it without a complete rebuild.

3. Works within HTML

Microdata can be convenient for projects where structured data is generated alongside the page’s HTML.

Limitations of Microdata

Microdata mixes structured data attributes with HTML. On complex pages, this can make the markup harder to read and maintain.

A developer changing a template may accidentally remove or alter an important attribute. Nested items can also make the HTML more complicated.

For these reasons, many teams prefer JSON-LD for new implementations, especially when structured data needs to be maintained independently from the page layout.

What Is RDFa?

RDFa stands for Resource Description Framework in Attributes. Like Microdata, it adds attributes to HTML elements to describe structured information and relationships.

Common RDFa attributes include:

• vocab: Defines the vocabulary used.
• typeof: Identifies the type of an item.
• property: Identifies a property.
• resource: Identifies a resource or related entity.

Example of RDFa

The same article can be described using RDFa:

<article vocab="https://schema.org/"
         typeof="Article">

  <h1 property="headline">
    A Beginner's Guide to Technical SEO
  </h1>

  <p property="description">
    Learn the basics of technical SEO.
  </p>

  <div property="author"
       typeof="Person">

    <span property="name">Alex Smith</span>

  </div>

  <meta property="datePublished"
        content="2026-10-01">

</article>

The vocab attribute declares Schema.org as the vocabulary. The typeof attribute identifies the Article and Person items, while property identifies their individual properties.

This is a simplified example. Real implementations should follow the requirements of the specific schema type and the relevant search feature.

Advantages of RDFa

1. Expresses relationships between entities

RDFa can describe how different entities and properties relate to one another.

2. Integrates with HTML

Like Microdata, RDFa associates structured information with HTML elements.

3. Useful in existing linked-data projects

RDFa may be appropriate for websites or applications that already rely on RDF-based data structures.

Limitations of RDFa

RDFa can be less familiar to SEO teams that primarily work with JSON-LD. Its attributes also become part of the HTML, which can increase template complexity.

For a typical business website or blog starting a new schema implementation, JSON-LD will often be the simpler choice.

The Same Schema in All Three Formats: What Changes?

The examples above describe the same basic Article information using different formats.

The underlying information remains similar:

• Article headline
• Article description
• Author name
• Publication date

What changes is the way the information is represented.

In JSON-LD, the data appears as a separate structured block. In Microdata, HTML attributes identify the item and its properties. In RDFa, attributes such as typeof, property, and vocab describe the information.

This distinction matters when choosing a format for a website with many pages.

For example, imagine an e-commerce website with hundreds of product pages. The team may need to describe product names, prices, availability, and other relevant details. JSON-LD can make it convenient to generate this data from product records without adding multiple attributes throughout the HTML template.

However, if the site already has a correct Microdata implementation, changing formats may introduce unnecessary work. A migration should have a clear benefit and include testing to confirm that the new implementation preserves the relevant information.

The important principle is consistency: whichever format you choose, the structured data must accurately represent the visible page content and meet the requirements of the relevant schema type and Google search feature.

Which Schema Format Should You Choose?

The best schema markup format for SEO depends on your website, existing implementation, and technical requirements. For most new implementations, JSON-LD is the recommended starting point.

Choose JSON-LD if:

• You are adding structured data to a new website.
• You want to keep schema markup separate from the HTML layout.
• Your CMS or SEO plugin supports reliable JSON-LD generation.
• Your team needs a straightforward way to update structured data.

Keep Microdata if:

• Your existing implementation is accurate and valid.
• Your templates already generate the required information correctly.
• A migration would add complexity without a clear benefit.

Consider RDFa if:

• Your project already relies on RDFa or linked-data workflows.
• Your developers have a specific technical reason to use it.
• Your implementation meets the relevant search engine requirements.

What about WordPress websites?

If you use WordPress, first check whether your SEO plugin or theme already generates schema markup. Adding another manual schema block without checking existing output can create duplicate or conflicting information.

For example, your SEO plugin may already output Article and Organization structured data. Adding another block that describes the same entities with different values could make the implementation harder to maintain.

Review the generated markup before making changes. If it is accurate and suitable, you may not need to add anything manually.

Does Schema Format Affect SEO Rankings or AI Search?

Structured data and SEO rankings are related, but they are not the same thing.

Correct structured data can help search engines interpret page information and may make eligible content qualify for certain rich results. However, choosing JSON-LD over Microdata or RDFa does not automatically improve a page’s ranking.

Google does not guarantee rich results even when structured data passes the Rich Results Test. The page must also meet applicable content policies, technical requirements, and feature-specific guidelines.

The same care is necessary when discussing AI search. Structured data can provide machine-readable information about entities and content, but it does not guarantee that an AI system will cite, mention, or recommend your website.

If you want to strengthen your website’s search visibility, focus on several areas together:

• Publish useful and reliable content.
• Make important pages accessible to search engines.
• Use accurate, relevant structured data.
• Improve internal linking and site organization.
• Follow technical SEO best practices.
• Monitor search performance and indexing issues.

You can also read DevEx’s guide to what E-E-A-T means for SEO to understand why experience, expertise, authoritativeness, and trust are important considerations when evaluating content quality.

How to Audit, Validate, and Migrate Schema Markup

Before adding or changing structured data, check what your website already uses. This helps prevent duplicate markup and unnecessary development work.

Step 1: Inspect the existing markup

Open a page on your website and inspect its HTML source or use your browser’s developer tools. Search for:

• application/ld+json for JSON-LD
• itemscope and itemprop for Microdata
• vocab, typeof, or property for RDFa

A page may contain more than one format. Finding multiple formats does not automatically mean there is an error, but you should check whether they describe the same information consistently.

Step 2: Validate the structured data

Use structured data validation tools to check your markup for errors and ensure it follows the correct format. Review the detected issues and fix any problems that could affect how search engines interpret your content.
Keep in mind that passing a validation test does not guarantee rich results, higher rankings, or full compliance with every search engine quality guideline.

Step 3: Check Google’s guidelines

Confirm that your markup:

• Describes content that is actually visible to users.
• Uses the correct type and applicable properties.
• Includes required properties for the relevant rich result.
• Is placed on the page it describes.
• Is not blocked from Googlebot by robots.txt noindexor other access controls.
• Uses accurate information and relevant images.

Step 4: Plan your migration

If you decide to migrate Microdata or RDFa to JSON-LD, follow a controlled process:

1. Record the existing schema types and properties.
2. Identify which properties are required or recommended for the intended feature.
3. Create equivalent JSON-LD using accurate page information.
4. Test the new markup before deployment.
5. Check that the rendered page does not contain unintended duplicate or conflicting data.
6. Revalidate the live page after deployment.
7. Monitor relevant reports in Google Search Console.

Do not remove existing markup blindly. Confirm that the replacement preserves the information your site needs.

Common Schema Markup Mistakes

Even the preferred format can fail when implemented incorrectly. Avoid these common mistakes:

1. Marking up hidden or irrelevant content: Structured data should accurately represent content users can access on the page.

2. Adding inaccurate information: Do not use fake reviews, misleading prices, or unrelated schema properties.

3. Missing required properties: Some rich result types require specific fields. Missing them can make the item ineligible.

4. Ignoring crawlability: Google must be able to access the page and relevant structured data resources.

5. Adding duplicate or conflicting markup: Multiple schema blocks are not inherently wrong, but inconsistent facts can create ambiguity.

6. Assuming valid schema guarantees rankings: Structured data is not a shortcut to top search positions or guaranteed rich results.

7. Forgetting to retest after changes: Themes, plugins, and template updates can alter schema output. Recheck important pages after significant changes.

FAQ

1. What is the difference between JSON-LD and Microdata?

   JSON-LD places structured data in a separate script block, while Microdata adds attributes directly to HTML elements. Both can describe information such as articles, products, and organizations when implemented correctly.

2.  Is JSON-LD better than Microdata for SEO?

   Google recommends JSON-LD when practical, mainly because it’s easier to implement and maintain separately from HTML. However, JSON-LD doesn’t automatically improve rankings, and valid Microdata can also qualify for supported rich results.

3.  Does Google support RDFa?

   Yes. Google supports RDFa, Microdata, and JSON-LD for structured data. JSON-LD is Google’s recommended format, but an existing RDFa implementation does not necessarily need to be replaced if it is correct and meets your requirements.

4.  Can you use JSON-LD and Microdata on the same page?

   Yes, a page can contain multiple structured data formats. However, the information should remain accurate and consistent. Avoid creating duplicate or conflicting descriptions of the same entities.

5.  How do you test structured data?

   Use Google’s Rich Results Test to check eligibility for supported rich results. Use the Schema.org Validator to inspect structured data vocabulary and markup. Also review Google’s content policies and the requirements for the specific schema type.

6.  Does schema markup improve Google rankings?

   Schema markup is not a guaranteed ranking boost. It can help search engines understand page content and make eligible pages qualify for certain rich results. Useful content, accessibility, technical quality, and compliance with Google’s guidelines remain important.

Conclusion

When comparing JSON-LD vs Microdata vs RDFa, JSON-LD is generally the best starting point for new SEO implementations because Google recommends it and it can be easier to maintain separately from the page’s HTML.

Microdata and RDFa remain supported options. If your existing implementation is accurate, accessible, and working as intended, you may not need to migrate simply because another format is available.

Choose the format that suits your website, keep the structured data consistent with visible content, and validate your implementation before and after deployment.

Most importantly, treat schema markup as one part of a wider SEO strategy rather than a guarantee of rankings or rich results.