HTTP Security Headers
app.google
app.google has no A or AAAA record, so nothing answers at app.google itself. These are the headers served at www.app.google.
Final status: 400 · Server: ESF
http://www.app.google (301)https://www.app.google/ (400)
Security Headers
Strict-Transport-Security (HSTS) — missing
Forces browsers to use HTTPS, preventing protocol-downgrade attacks.
Content-Security-Policy (CSP)
Limits where scripts/resources can load from — the strongest defense against XSS.
X-Frame-Options SAMEORIGIN
Blocks the site from being embedded in iframes (clickjacking protection).
X-Content-Type-Options
Stops browsers from MIME-sniffing responses away from the declared type.
Referrer-Policy — missing
Controls how much referrer information is sent to other sites.
Permissions-Policy
Restricts access to browser features like camera, microphone, geolocation.