Why Structured data (JSON-LD) in NextJS? - Purpose & Use Cases

The Big Idea

Discover how a simple script can make your website shine in search results!

The Scenario

Imagine you have a website with many pages, and you want search engines to understand your content better to show rich results.

You try adding hidden text or meta tags manually on each page.

The Problem

Manually adding hidden text or meta tags is confusing and easy to get wrong.

Search engines might miss important info or misunderstand your content, hurting your site's visibility.

The Solution

Structured data using JSON-LD lets you add clear, standardized information about your page in a simple script format.

This helps search engines understand your content automatically and accurately.

Before vs After

✗ Before

<meta name="description" content="Best coffee shop in town">
<meta name="author" content="Cafe Owner">

✓ After

<script type="application/ld+json">{"@context":"https://schema.org","@type":"Cafe","name":"Best Coffee Shop"}</script>

What It Enables

It enables search engines to show rich snippets like ratings, opening hours, and more, making your site stand out.

Real Life Example

A local bakery adds JSON-LD structured data to show their menu and reviews directly in Google search results, attracting more customers.

Key Takeaways

Manual metadata is error-prone and limited.

JSON-LD provides a clear, standard way to describe your content.

It improves search engine understanding and boosts your site's visibility.

Practice

1. What is the main purpose of adding JSON-LD structured data in a Next.js page?

easy

A. To improve server response time

B. To help search engines understand the page content better

C. To add interactive animations to the page

D. To style the page with custom CSS

Solution

1. Step 1: Understand JSON-LD role

   JSON-LD is a format for structured data that helps search engines understand the content of a webpage.

2. Step 2: Identify its use in Next.js

   In Next.js, JSON-LD is used to improve SEO by providing clear data to search engines, not for styling or animations.

3. Final Answer:

   To help search engines understand the page content better -> Option B

4. Quick Check:

   JSON-LD purpose = SEO improvement [OK]

Hint: JSON-LD is for SEO, not styling or animations [OK]

Common Mistakes:

• Confusing JSON-LD with CSS or JavaScript animations
• Thinking JSON-LD speeds up server response
• Assuming JSON-LD changes page appearance

2. Which is the correct way to include JSON-LD structured data in a Next.js component?

easy

A.

B.

C.

D.

Solution

1. Step 1: Use Next.js Script component

   Next.js provides the Script component from next/script to safely add scripts including JSON-LD.

2. Step 2: Use dangerouslySetInnerHTML correctly

   JSON-LD must be added as a string inside dangerouslySetInnerHTML to avoid React escaping it.

3. Final Answer:

   <Script type="application/ld+json" dangerouslySetInnerHTML={{ __html: JSON.stringify(data) }} /> -> Option C

4. Quick Check:

   Use Next.js Script + dangerouslySetInnerHTML [OK]

Hint: Use Next.js Script with dangerouslySetInnerHTML for JSON-LD [OK]

Common Mistakes:

• Using lowercase <script> tag directly in JSX
• Not using dangerouslySetInnerHTML for JSON-LD
• Forgetting to import Script from next/script

3. Given this Next.js code snippet, what will be the rendered output in the HTML?

import Script from 'next/script';

const data = {"@context": "https://schema.org", "@type": "Person", "name": "Alice"};

export default function Page() {
  return (
    <>
      <h1>Profile</h1>
      <Script type="application/ld+json" dangerouslySetInnerHTML={{ __html: JSON.stringify(data) }} />
    </>
  );
}

medium

A. Profile

B. Profile

C. Profile

D. Profile

Solution

1. Step 1: Understand Script output

   The Next.js Script component renders a <script> tag with the specified type and inner HTML.

2. Step 2: Check JSON-LD content

   The JSON-LD data is stringified and inserted as raw JSON inside the script tag with type application/ld+json.

3. Final Answer:

   <h1>Profile</h1><script type="application/ld+json">{"@context":"https://schema.org","@type":"Person","name":"Alice"}</script> -> Option D

4. Quick Check:

   JSON-LD script tag with stringified data [OK]

Hint: JSON-LD renders as script with type and stringified JSON [OK]

Common Mistakes:

• Using wrong script type attribute
• Rendering JSON object instead of string
• Placing JSON inside curly braces in HTML output

4. What is wrong with this Next.js code for adding JSON-LD?

import Script from 'next/script';

const data = {"@context": "https://schema.org", "@type": "Organization", "name": "My Company"};

export default function Home() {
  return (
    <Script type="application/ld+json">{JSON.stringify(data)}</Script>
  );
}

medium

A. Using <Script> without dangerouslySetInnerHTML causes JSON to render as text, not script content

B. Missing import of React causes error

C. JSON.stringify should not be used inside Script

D. Script component must be self-closing

Solution

1. Step 1: Check Script usage

   The Script component requires dangerouslySetInnerHTML to insert raw JSON-LD content inside the script tag.

2. Step 2: Identify the error

   Passing JSON string as children renders it as text inside the script tag, which is invalid for JSON-LD.

3. Final Answer:

   Using <Script> without dangerouslySetInnerHTML causes JSON to render as text, not script content -> Option A

4. Quick Check:

   Use dangerouslySetInnerHTML for JSON-LD scripts [OK]

Hint: Always use dangerouslySetInnerHTML for JSON-LD in Script [OK]

Common Mistakes:

• Passing JSON as children instead of dangerouslySetInnerHTML
• Forgetting to stringify JSON data
• Assuming Script auto-inserts raw JSON

5. You want to add multiple JSON-LD scripts for different entities on a Next.js page. Which approach correctly adds two JSON-LD scripts safely?

hard

A. Use two <Script> components each with type="application/ld+json" and dangerouslySetInnerHTML containing separate JSON objects

B. Combine both JSON objects into one and add a single <Script> with dangerouslySetInnerHTML

C. Add one <Script> with an array of JSON objects inside dangerouslySetInnerHTML

D. Add JSON-LD as inline JavaScript variables inside a single <Script> tag

Solution

1. Step 1: Understand JSON-LD script requirements

   Each JSON-LD script tag should contain a single JSON object describing one entity for clarity and correctness.

2. Step 2: Use multiple Script components

   In Next.js, you can safely add multiple Script components each with their own JSON-LD data using dangerouslySetInnerHTML.

3. Final Answer:

   Use two <Script> components each with type="application/ld+json" and dangerouslySetInnerHTML containing separate JSON objects -> Option A

4. Quick Check:

   Multiple Script tags with separate JSON-LD objects [OK]

Hint: Use separate Script tags for each JSON-LD object [OK]

Common Mistakes:

• Putting multiple JSON objects in one script tag without array
• Using arrays inside JSON-LD script which is invalid
• Embedding JSON-LD as JS variables instead of script content