JSON-LD structured data check for common rich result types

What it does

Extracts and checks the JSON-LD structured data embedded in pages.

• Finds every <script type="application/ld+json"> block and reports JSON syntax errors with line and column, plus the likely cause (trailing comma, typographic quotes and so on)
• Walks @graph, arrays, nested objects and @id references to find each entity
• Uses a bundled rule table to list missing required and recommended properties for Product, Article (NewsArticle, BlogPosting), BreadcrumbList, FAQPage, Organization and SoftwareApplication, including nested Offer, rating, review and breadcrumb items
• Checks value formats: ISO 8601 dates, absolute URLs, plain numeric prices, currency codes, availability values
• The agent then proposes corrected JSON-LD

How to use

python scripts/jsonld_check.py https://example.com/products/1 --out jsonld.json
python scripts/jsonld_check.py ./dist --quiet-recommended

Requirements

• Python 3 (standard library only)
• Network access when checking live URLs

Caveats

• Only JSON-LD is read (not Microdata or RDFa). Markup injected by JavaScript does not appear in raw HTML.
• Google retired FAQ rich results in 2026; FAQPage is checked for structure only and flagged as such.
• Valid markup does not guarantee a rich result. Confirm with Google's Rich Results Test.
• The rule table summarizes Google's documentation as of November 2026.