What Are HTTP Headers?
HTTP headers are metadata sent between the browser and server with every request and response. They control caching, authentication, content type, security policies, and more. Inspecting headers helps diagnose performance issues and verify security configurations.
Important Security Headers
- Strict-Transport-Security — Forces HTTPS connections, preventing downgrade attacks
- Content-Security-Policy — Controls which resources the browser can load
- X-Frame-Options — Prevents clickjacking by controlling iframe embedding
- X-Content-Type-Options — Prevents MIME-type sniffing attacks
- Referrer-Policy — Controls how much referrer info is sent with requests