What are HTTP Headers?
HTTP headers are additional pieces of information sent between a client (browser) and server during an HTTP request/response. They provide metadata about the request or response, such as content type, caching policies, security settings, and more.
Important Security Headers:
- Strict-Transport-Security (HSTS) - Forces HTTPS connections
- Content-Security-Policy (CSP) - Prevents XSS and injection attacks
- X-Frame-Options - Protects against clickjacking
- X-Content-Type-Options - Prevents MIME type sniffing
- Referrer-Policy - Controls referrer information
- Permissions-Policy - Controls browser features and APIs
Why Check HTTP Headers?
- Verify security headers are properly configured
- Troubleshoot caching and performance issues
- Check server and technology stack information
- Debug CORS and authentication problems
- Ensure proper content type settings
- Analyze redirect chains and status codes