SECURITY HEADERS

Security Headers Checker

Scan any website's HTTP response headers and get an instant A+ to F security grade β€” HSTS, CSP, X-Frame-Options and more, with a fix for anything missing.

Enter any public domain or URL. We fetch it once from the edge and grade its response headers β€” nothing is stored.

WHAT WE CHECK

The six headers that decide your grade

Each one closes a specific class of attack. Here's what they do and why they matter.

Strict-Transport-Security

Forces browsers to use HTTPS only, blocking downgrade and cookie-hijacking attacks. Add it with a max-age of at least 6 months.

Content-Security-Policy

Controls which scripts, styles and resources may load β€” the strongest defense against cross-site scripting (XSS) and injection.

X-Content-Type-Options

Stops browsers from MIME-sniffing responses, which can turn an uploaded file into executable script. Set it to nosniff.

X-Frame-Options

Prevents your pages from being embedded in other sites' frames, blocking clickjacking. Use X-Frame-Options or CSP frame-ancestors.

Referrer-Policy

Controls how much of your URL is sent to other sites when users click links, protecting private paths and tokens.

Permissions-Policy

Restricts which browser features (camera, microphone, geolocation, and more) a page and its embeds are allowed to use.

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Security Headers Checker β€” Grade Any Site A+ to F | whatsmy.fyi