Broken Link Scan

Broken Link Scan

Find every dead or misbehaving link on a page. No signup required.

Prerequisites

• Playwright MCP (bundled with Claude Code)
• curl on PATH (external links and redirect-hop counting)

Trigger

• "Find broken links on https://example.com"
• "Check my site for 404s"
• "Scan this page's links"
• "Any dead links on the docs?"

Workflow

1. Navigate to the target URL with mcp__playwright__browser_navigate.
2. Collect, dedupe, and check internal links in one mcp__playwright__browser_evaluate call. Page-context fetch carries session cookies, so auth-gated internal pages check correctly. HEAD first; on 405 Method Not Allowed (RFC 9110 §15.5.6) fall back to GET:

async () => {
  const seen = new Map();
  for (const a of document.querySelectorAll('a[href]')) {
    let u; try { u = new URL(a.href, location.href); } catch { continue; }
    if (!/^https?:$/.test(u.protocol)) continue;   // skip mailto:, tel:, javascript:
    u.hash = '';                                   // fragment-only variants are duplicates
    if (!seen.has(u.href)) seen.set(u.href, {
      href: u.href, text: a.textContent.trim().slice(0, 60),
      internal: u.host === location.host,
      insecure: u.protocol === 'http:' && location.protocol === 'https:',
    });
  }
  const links = [...seen.values()].slice(0, 50);   // cap: 50 links per page
  const check = async l => {
    try {
      let r = await fetch(l.href, { method: 'HEAD', redirect: 'follow' });
      if (r.status === 405 || r.status === 501) r = await fetch(l.href, { redirect: 'follow' });
      return { ...l, status: r.status, redirected: r.redirected, finalUrl: r.url };
    } catch (e) { return { ...l, status: 0, error: String(e) }; }
  };
  const internal = links.filter(l => l.internal), results = [];
  for (let i = 0; i < internal.length; i += 5)
    results.push(...await Promise.all(internal.slice(i, i + 5).map(check)));
  return { results, external: links.filter(l => !l.internal).map(l => l.href),
           insecure: links.filter(l => l.insecure).map(l => l.href),
           totalUnique: seen.size, capped: seen.size > 50 };
}

3. Check each external link from bash — page-context fetch cannot read cross-origin status codes (CORS yields opaque responses), so curl is the honest path. HEAD, then GET fallback:

curl -sIL -m 10 -o /dev/null -w '%{http_code} %{num_redirects} %{url_effective}\n' "$URL"
# if that prints 405: curl -sL -m 10 -o /dev/null -w '%{http_code} %{num_redirects} %{url_effective}\n' "$URL"

4. For each internal link that reported redirected: true, count hops — fetch only exposes the final URL, not chain length: curl -s -o /dev/null -L --max-redirs 10 -w '%{num_redirects}' "$URL"
5. Classify every checked link:
   • Broken — 404, 410 Gone, or network error/timeout (status 0)
   • Server error — any 5xx
   • Redirect chain — more than 2 hops; each hop costs a round trip (Lighthouse: "avoid multiple page redirects")
   • Insecure — http:// link on an https:// page, downgrading users off TLS
6. Grade: A all clean · B only 1–2-hop redirects · C chains >2 hops or insecure links · D 1–2 broken links · F 3+ broken or any 5xx.

Report

## Broken Link Report: {URL}

**Grade: {A–F}** — {one-line reason}
Checked {n} of {totalUnique} unique links ({internal} internal, {external} external). Cap is 50/page{ — page exceeded it; rerun on subpages for full coverage}.

### Broken ({n})
| Link text | URL | Status |
|---|---|---|
| "Old docs" | /docs/v1 | 404 |

### Redirect chains >2 hops ({n})
- /blog → 3 hops → /articles/blog — link the final URL directly

### Insecure http links on https page ({n})
- http://partner.example.com — upgrade to https or remove

### Limits
- Soft 404s (200 status with a "not found" body) are invisible to status checks — spot-check odd `finalUrl`s.
- External statuses come from curl without your session cookies; login-walled externals may report 401/403.

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