ogpeek

peek into any page's Open Graph tags — and the favicon / JSON-LD signals that travel with them

Korean: README.ko.md

A focused OpenGraph debugging tool: paste a URL, see exactly how the page's OG card will render, and get OGP-spec violations called out automatically. Open Graph stays the primary signal; ogpeek also surfaces the auxiliary head metadata most pages ship with — favicons / apple-touch-icons / mask-icons, msapplication tiles, application-name / theme-color, and JSON-LD blocks — so "how does this page advertise itself elsewhere?" debugging stays in one place.

Layout

• packages/ogpeek — the pure engine that handles fetch · parse · validate. This is the body of the repo. Single external dependency: htmlparser2. Node 22.19+ (development is on Node 24 LTS).
• packages/ogpeek-react — drop-in React components that render the engine's results.
• packages/ogpeek-extension — cross-browser MV3 extension that ships the engine in the user's own browser, so it can inspect intranet hosts that the public demo can't reach. v1 builds Chrome only; Firefox / Safari manifests are scaffolded for follow-up.
• website — a demo site built on Next.js 15 (App Router). It exists as a usage example for the engine and as a landing page. Deployed only to Cloudflare Workers (via OpenNext).

Quick start

pnpm install
pnpm -F website dev               # http://localhost:3000
pnpm -F ogpeek test               # engine unit tests
pnpm -F ogpeek-extension build    # Chrome MV3 unpacked at packages/ogpeek-extension/dist/chrome

Validation rules at a glance

The rules maintained in packages/ogpeek/src/validate.ts:

• OG_TITLE_MISSING / OG_TITLE_TOO_LONG (over 60 chars — KakaoTalk truncates)
• OG_TYPE_MISSING / OG_TYPE_UNKNOWN
• OG_IMAGE_MISSING
• OG_URL_MISSING / OG_URL_MISMATCH (og:url disagrees with the actual request URL)
• URL_NOT_ABSOLUTE / DUPLICATE_SINGLETON / ORPHAN_STRUCTURED_PROPERTY / INVALID_DIMENSION
• MISSING_PREFIX_ATTR (info)
• JSONLD_PARSE_ERROR (a <script type="application/ld+json"> block did not parse)

See packages/ogpeek/README.md for full descriptions.

Scripts

pnpm -r typecheck        # workspace-wide tsc --noEmit
pnpm -F ogpeek test      # engine unit tests
pnpm -F website cf:build # OpenNext + Workers bundle

License

MIT.