HTTP Headers Checker

HTTP headers are metadata exchanged between a client (browser) and server with every request and response. They control caching, authentication, security policies, content negotiation, and more.

Key Security Headers

• Strict-Transport-Security (HSTS): Forces browsers to use HTTPS, preventing downgrade attacks
• Content-Security-Policy (CSP): Controls which resources can be loaded, preventing XSS attacks
• X-Content-Type-Options: Prevents browsers from MIME-sniffing the content type
• X-Frame-Options: Prevents clickjacking by controlling iframe embedding
• Referrer-Policy: Controls how much referrer information is sent with requests

Caching Headers

• Cache-Control: Directives for how and how long to cache content
• ETag: Identifier for a specific version of a resource
• Expires: Date/time after which the response is considered stale