HTTP Header Security Analyzer

HTTP security headers are configuration directives sent by web servers to instruct browsers on how to behave when rendering web content. They protect applications against XSS, clickjacking, MIME sniffing, and protocol downgrade attacks.

The analyzer inspects your header payload against OWASP benchmarks, assigning weighted penalty points for missing critical headers (like CSP and HSTS) or insecure configurations.

HTTP Strict Transport Security (HSTS) tells browsers to only communicate over HTTPS. A robust configuration includes a long max-age (e.g., 31536000 seconds), includeSubDomains, and preload directives.

CSP restricts the domains from which scripts, stylesheets, and images can be loaded and executed, effectively stopping Cross-Site Scripting (XSS) and unauthorized data exfiltration.

X-Frame-Options specifies whether a web page can be embedded inside an iframe on another domain. Setting it to DENY or SAMEORIGIN prevents malicious sites from overlaying invisible frames over your application.

The nosniff directive prevents browsers from guessing or "sniffing" files' MIME types, forcing them to strictly adhere to the declared Content-Type header and preventing malicious script uploads.

Referrer-Policy controls how much referrer information (which includes full URLs and query parameters) is included with navigation requests, protecting sensitive user data from leaking to third parties.

Permissions-Policy restricts browser features and APIs—such as geolocation, microphone, camera, and payment gateways—from being accessed by embedded third-party scripts or ad networks.

Yes. You can paste raw response headers captured from local proxies, curl commands, or browser developer tools directly into the text area for offline auditing.

Completely. All analysis routines execute locally within your web browser using client-side JavaScript, ensuring zero data transmission to external logging servers.

Security headers in Nginx are added within your server or location blocks using the add_header directive, for example: add_header X-Frame-Options "SAMEORIGIN" always;.

Apache headers are configured using the Header module in your .htaccess or virtual host configuration file, such as: Header always set X-Content-Type-Options "nosniff".

HPKP was an older header designed to prevent fraudulent SSL certificates, but it has been deprecated by major browsers due to the high risk of self-inflicted denial-of-service if misconfigured. Certificate Transparency logs have replaced it.

X-XSS-Protection is an older, largely obsolete header for legacy browsers. Modern security standards rely entirely on robust Content Security Policies (CSP) for XSS defense.

Leaving detailed version numbers in the Server or X-Powered-By headers aids attackers in identifying known software vulnerabilities associated with specific web server builds.

Cross-Origin Resource Sharing (CORS) headers (like Access-Control-Allow-Origin) govern how APIs share resources across domains, requiring careful configuration to prevent unauthorized cross-origin data exposure.

Preloading allows browsers to hardcode your domain into an official HSTS preload list, ensuring that even the very first connection to your website is forced over HTTPS.

No. Security headers protect the transport layer and client-side browser execution. Backend vulnerabilities like SQL injection require secure coding practices and parameterized queries.

Security headers should be audited continuously during CI/CD builds, as part of routine vulnerability scans, and whenever reverse proxy or load balancer configurations are updated.

The OWASP Secure Headers Project is an open initiative that defines standardized guidelines and documentation for implementing defense-in-depth response headers across web applications.