Structured Data Basics: JSON-LD vs Microdata and When It Matters

TL;DR (Key takeaways)

• Google explains structured data as a way to describe content using a standardized format so search engines can understand it. (Intro to structured data)
• JSON-LD is often easiest to implement because it can live in the HTML without tightly coupling to markup, but the best format is the one you can keep correct as templates evolve.
• Structured data is about eligibility and clarity — it does not guarantee a specific appearance in results.
• Validate routinely with the Rich Results Test and Schema Validator.

What we know (from primary sources)

Google’s documentation introduces structured data and describes how it helps search engines understand page content. It also provides implementation examples for various structured data types and eligibility for rich results. (Google: structured data intro)

Schema vocabulary itself is maintained by Schema.org, which defines types (e.g., Article, Organization, Product) and properties (e.g., author, brand, sameAs).

JSON-LD vs Microdata (practical differences)

JSON-LD

JSON-LD typically lives in a <script type="application/ld+json"> block. Operationally, it’s easy to version and test because it’s a single blob that templates can generate.

Microdata

Microdata is embedded directly in HTML attributes. Some teams prefer it because it is “attached” to the visible elements — but it can be more fragile when front-end refactors happen.

How to choose the right starting schema

Start with the schema types that match your content and have clear value:

• Editorial content: Article schema
• Brand/entity: Organization schema
• Ecommerce: Product schema
• Navigation: Breadcrumb schema

For a cohesive implementation plan, use our hub guide: Structured Data Playbook.

Validation workflow (simple and repeatable)

1. Validate page-level markup with Google’s Rich Results Test. (Rich Results Test)
2. Validate general schema syntax with the Schema Validator. (Schema Validator)
3. Re-test after template changes, CMS updates, and AI-generated layout refactors.

What’s next

Structured data works best when it’s part of your release process. If your team ships frequently (or uses AI-generated code), add schema checks to your QA checklist and connect it to your technical baseline: Technical SEO Checklist.

Why it matters

Structured data is one of the most direct ways to express “what this page is” in machine-readable form. That matters for classic rich results, and it’s also a helpful clarity layer when you want AI systems to recognize and cite your primary entities and source pages.

For broader AI search context, see AI & SEO trends and AI search monitoring strategy.