Social Preview Inspector

Fetch any URL and extract og:*, twitter:*, <title>, and meta description tags with HTMLRewriter. Returns side-by-side preview validation for Twitter/X, Open Graph (Facebook/Slack), and Google search snippets, flagging missing required fields per platform.

FeaturesCopy Anchor Link

• GET /inspect - extract meta tags and validate per-platform preview requirements
• Side-by-side Twitter, Open Graph, and Google preview objects
• Flags missing and fallback fields (e.g. og:title used when twitter:title absent)

API ReferenceCopy Anchor Link

GET /inspectCopy Anchor Link

Fetch a page and return social preview validation for three platforms.

Example RequestCopy Anchor Link

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

Success ResponseCopy Anchor Link

{
  "url": "https://example.com/",
  "extracted": { "title": "Example", "description": "...", "openGraph": {}, "twitter": {} },
  "previews": {
    "openGraph": { "platform": "openGraph", "valid": true, "missing": [], "fields": {} },
    "twitter": { "platform": "twitter", "valid": false, "missing": ["image"], "fields": {} },
    "google": { "platform": "google", "valid": true, "missing": [], "fields": {} }
  }
}

Error CodesCopy Anchor Link

• 400 - INVALID_URL
• 502 - FETCH_ERROR

Use CasesCopy Anchor Link

• Debug why a link unfurls incorrectly on Slack, Twitter, or iMessage
• Audit marketing pages for missing Open Graph or Twitter Card tags
• Compare Google snippet fields against social preview metadata

LimitationsCopy Anchor Link

• Uses raw HTML fetch; does not execute JavaScript (client-rendered tags may be missing)
• Single URL per request; no batch inspection
• Platform validation rules are heuristic, not identical to each platform's renderer

Use in your projectCopy Anchor Link

import { FETCH_TIMEOUT_MS } from "../constants/defaults";export async function fetchHtml(url: string): Promise<string> {  const controller = new AbortController();  const timeout = setTimeout(() => controller.abort(), FETCH_TIMEOUT_MS);  try {    const res = await fetch(url, {      headers: {        Accept: "text/html,application/xhtml+xml",        "User-Agent": "social-preview-inspector/1.0",      },      signal: controller.signal,      redirect: "follow",    });    clearTimeout(timeout);    if (!res.ok) {      throw new Error(`Upstream returned HTTP ${res.status}`);    }    return await res.text();  } catch (err) {    clearTimeout(timeout);    if (err instanceof Error && err.name === "AbortError") {      throw new Error("Request timed out");    }    throw err instanceof Error ? err : new Error("Failed to fetch URL");  }}

DeploymentCopy Anchor Link

Local DevelopmentCopy Anchor Link

cd apps/experiments/social-preview-inspector
npm install
npm run dev

ConfigurationCopy Anchor Link

No bindings required beyond the Workers runtime.

Cloudflare Features UsedCopy Anchor Link

• Workers
• HTMLRewriter