Security Headers Checker

Scan any website's HTTP security headers and get an instant grade with actionable recommendations.

Monitor Your Security Posture

Security headers are just the beginning. ObserveOne monitors your entire application stack, uptime, performance, and security, around the clock.

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Side-by-side breakdowns, no fluff.

Why Security Headers Matter

HTTP security headers are your first line of defense against common web attacks like cross-site scripting (XSS), clickjacking, and protocol downgrade attacks. They instruct browsers on how to behave when handling your site's content, significantly reducing your attack surface with minimal implementation effort.

Essential Security Headers

Strict-Transport-Security

Forces browsers to only connect via HTTPS, preventing protocol downgrade attacks and cookie hijacking.

Content-Security-Policy

Controls which resources the browser is allowed to load, preventing XSS and data injection attacks.

X-Frame-Options

Prevents your site from being embedded in iframes, protecting against clickjacking attacks.

X-Content-Type-Options

Prevents browsers from MIME-sniffing the content type, reducing exposure to drive-by download attacks.

Referrer-Policy

Controls how much referrer information is included with navigation requests, protecting user privacy.

Permissions-Policy

Controls which browser features and APIs can be used, limiting exposure to feature abuse.

What This Tool Checks

Header Presence

Verifies that all recommended security headers are present in your server's response.

Configuration Quality

Checks for weak configurations like missing includeSubDomains in HSTS or unsafe-inline in CSP.