# JSON-LD

Structured data describing what this page is about.

**[Content](/docs/content)** · checked on every URL · 6 checks that can fail it

It is the one part of a page an agent can read without interpreting prose, so a syntax error or a missing required property costs the whole block. We check the shapes with published required properties, not everything a vocabulary permits.

## Adoption

**Web baseline** (L4)

Standard equipment on the web. Its absence is the exception rather than its presence. Direction of travel: ► flat, as of 2026-07-28.

JSON-LD is on roughly 41% of pages (Web Almanac 2024, HTTP Archive, about 16M sites).

## What we check

Absence is never a finding: every check below runs only once `jsonLdPresent` is true, so a site that has not
adopted this is not assessed on it and appears in no report.

| Check | Kind | Raises | On whose authority |
|---|---|---|---|
| `jsonLdInvalidJson` | high severity | conformance, usability | specification (JSON-LD 1.1) |
| `jsonLdMissingContext` | medium severity | usability | Lumar readiness profile |
| `jsonLdMissingType` | medium severity | usability | Lumar readiness profile |
| `jsonLdMissingRequiredProp` | medium severity | usability | Google Search profile |
| `jsonLdInvalidValueFormat` | medium severity | usability | Schema.org profile |
| `jsonLdNonSchemaContext` | low severity | usability | Lumar readiness profile |

## Examples

These are the fixtures the test suite runs through the real collector, not snippets written for a document.

- Correct: `test/e2e/test-pages/content/correct.html`
- Present but wrong: `test/e2e/test-pages/content/issues.html`

## Specifications

| Document | Revision | Kind |
|---|---|---|
| [JSON-LD 1.1](https://www.w3.org/TR/json-ld11/) | W3C Recommendation | specification |
| [Schema.org](https://schema.org/) | v30.0 | specification |
| [Google Search: Recipe structured data](https://developers.google.com/search/docs/appearance/structured-data/recipe) | living document | vendor profile |
| [Google Search: Event structured data](https://developers.google.com/search/docs/appearance/structured-data/event) | living document | vendor profile |
| [Schema.org Date and DateTime (ISO 8601)](https://schema.org/Date) | v30.0 | specification |
| [Google Search: Article structured data (states no required properties, which is why we check none)](https://developers.google.com/search/docs/appearance/structured-data/article) | living document | vendor profile |

Last re-read against the published documents: 2026-08-12.