JSON-LD and Structured Data Formats

4 min lesson
3 activities
Updated October 21, 2026
By Remar Barquilla

What we will go through

The three structured data formats
How to read a JSON-LD block
How @id and @graph connect entities
Which format to recommend

Short answer

Structured data comes in three formats: JSON-LD, a separate script block; Microdata, attributes inside HTML tags; and RDFa, a similar attribute-based method. Google supports all three but recommends JSON-LD because it is easier to add, read, and maintain. Audits often find mixed formats, which increases the risk of duplicate or conflicting markup.

You will meet three formats in audits. Being able to read each one quickly is a core auditing skill.

JSON-LD (recommended)

<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "LocalBusiness",
  "@id": "https://www.example.ph/#business",
  "name": "Mayon View Cafe",
  "telephone": "+63 917 000 0000",
  "address": {
    "@type": "PostalAddress",
    "streetAddress": "Rizal Street",
    "addressLocality": "Legazpi City",
    "addressRegion": "Albay",
    "addressCountry": "PH"
  }
}
</script>

Read it top down: @type says what it is, each key is a property, nested objects have their own @type.

Microdata

<div itemscope itemtype="https://schema.org/LocalBusiness">
  <h1 itemprop="name">Mayon View Cafe</h1>
  <span itemprop="telephone">+63 917 000 0000</span>
</div>

RDFa

Uses vocab, typeof, and property attributes. Less common, mostly in older CMS themes.

Connecting entities

Large sites use @graph to hold several entities (Organization, WebSite, WebPage, Product) and @id to link them, so the Product can say its brand is the Organization’s @id. SEO plugins like Yoast and Rank Math output this pattern.

Practice: which format?

Sort each item into the right group.

<script type="application/ld+json">
itemprop="price"
typeof="Product"
"@graph": [ ... ]
itemscope itemtype="https://schema.org/Review"

Common mistakes

Theme Microdata plus plugin JSON-LD describing the same product twice.
JSON-LD only injected by tag managers without checking rendering.
Broken JSON from a missing comma or quote.

1. Which format does Google recommend?

2. What does @id do?

3. Risk of mixing formats?

Your action

View source on a product or service page Note which formats appear Read one JSON-LD block and list its types

Next, you will find structured data across a whole website.

Key terms

JSON-LD: Structured data written as JSON inside a <script type="application/ld+json"> tag.
Microdata: Structured data added with itemscope, itemtype, and itemprop attributes on HTML elements.
@id: A unique identifier for an entity, letting other blocks reference it.
@graph: A JSON-LD array holding several connected entities in one block.

Questions beginners ask

Can JSON-LD be added by JavaScript?

Yes, Google can read it after rendering. Server-rendered JSON-LD is more reliable and visible to non-rendering crawlers.

Is Microdata wrong?

No, it is valid. It is harder to maintain because it is tied to the HTML layout.

Can I mix formats on one page?

You can, but it often creates duplicate entities. Prefer one format per entity.

Where should JSON-LD go?

In the head or body. Location does not matter to Google.

Related lessons

Want someone to handle SEO for your business while you learn? The team at Remar Digital can help.