JSON-LD Extractor

Fetch a webpage and extract application/ld+json structured data blocks for Schema.org / rich-results debugging from Cloudflare's edge.

Features

• Parses all script[type="application/ld+json"] blocks
• Collects @type values including nested @graph
• Reports invalid JSON blocks without failing the whole response
• Caps extraction at 25 script blocks
• Stateless; no bindings required

API Reference

GET /extract

Fetches HTML and returns parsed JSON-LD blocks plus discovered types.

Example Request

curl "https://your-worker.workers.dev/extract?url=https://www.cloudflare.com"

Success Response

url string

Final page URL after redirects

count number

Number of JSON-LD script blocks found

types string[]

Sorted unique @type values across all blocks (including @graph)

blocks array

Per-block results with index, types, data, and optional parseError

{
  "url": "https://www.cloudflare.com/",
  "count": 2,
  "types": ["Organization", "WebSite"],
  "blocks": [
    {
      "index": 0,
      "types": ["Organization"],
      "data": {
        "@context": "https://schema.org",
        "@type": "Organization",
        "name": "Cloudflare"
      }
    },
    {
      "index": 1,
      "types": ["WebSite"],
      "data": {
        "@context": "https://schema.org",
        "@graph": [{ "@type": "WebSite", "name": "Cloudflare" }]
      }
    }
  ]
}

Error Response

{
  "error": "Expected HTML, got content-type: application/json",
  "code": "NOT_HTML"
}

Error Codes

• 400 - Missing or invalid url (INVALID_URL)
• 400 - Response was not HTML (NOT_HTML)
• 502 - Fetch failed (FETCH_ERROR)

Use Cases

• Debug rich results / Schema.org markup
• Inventory Organization, Product, Article entities on a site
• Complement Open Graph previews with structured data
• Build SEO auditing tools on Workers

Limitations

• Does not execute JavaScript-injected JSON-LD
• Caps extraction at 25 script blocks
• Does not validate against Schema.org vocabularies
• Invalid JSON blocks are reported via parseError rather than failing the request

Deployment

curl "https://your-worker.workers.dev/extract?url=https://example.com"

Local Development

cd apps/experiments/json-ld-extractor
npm install
npm run dev

Test locally:

curl "http://localhost:8787/extract?url=https://www.cloudflare.com"

Cloudflare Features Used

• Workers - Edge compute runtime
• Fetch API - HTML retrieval from the edge

Next Steps