Grade any site's security headers in 10 seconds.

Paste raw HTTP response headers — the tool gives a letter grade across 16 modern security headers, explains what each finding means, and shows the exact fix.

● Offline No network 16 headers analyzed CSP · HSTS · COOP · COEP · CORP · Permissions-Policy

Paste raw response headers

Headers come from curl -sIL https://your-site.example/, browser devtools Network tab → Response headers, or your CDN dashboard. Case-insensitive. Whitespace fine.