HTTP Headers Reference

A practical reference for HTTP headers covering caching, security, authentication, content negotiation, and CORS. Get quick explanations and correct usage for any HTTP header.

Usage

Ask about specific HTTP headers, their correct values, or which headers to use for specific purposes like caching or security.

Examples

• "What Cache-Control headers should I use for static assets?"
• "Explain all the security headers I should set"
• "What is the correct way to set CORS headers?"

Guidelines

• Always set security headers: Content-Security-Policy, X-Frame-Options, etc.
• Use Cache-Control for caching instead of the deprecated Expires header
• Set appropriate Content-Type headers with charset for text responses
• Use Vary header correctly to prevent cache poisoning
• Test header configurations with browser developer tools or curl