JSON-LD is a JSON-based format for adding linked data to a web page. In everyday web production, it is commonly used to output Schema.org structured data without mixing the data directly into visible HTML markup.
JSON-LD keeps structured data separate
Unlike microdata, which adds attributes to HTML elements, JSON-LD is usually placed in a script tag. That makes it easier to generate from templates, components, or content models while keeping the visible page markup clean.
{
"@context": "https://schema.org",
"@type": "Article",
"headline": "What Is JSON-LD?",
"datePublished": "2026-05-07",
"author": {
"@type": "Organization",
"name": "TOOLPOOL"
}
}Check @context and @type first
@context tells consumers which vocabulary the data uses. For Schema.org structured data, it is usually https://schema.org. @type tells them what the item represents, such as Article, WebSite, BreadcrumbList, or SoftwareApplication.
JSON-LD checklist
- The script type is application/ld+json
- The JSON parses without errors
- @context and @type are present
- Structured data does not claim content that is missing from the page
- Old JSON-LD is not left behind after template changes
Because JSON-LD is not visible on the page, broken or outdated data can be easy to miss. Use the TOOLPOOL Schema Checker to extract JSON-LD from a public URL and review detected types and properties before publishing.