HTTP Headers Lookup
A reference manual for common HTTP request and response headers. Browse by category — General, Request, Response, CORS, and Caching — and click any header to copy its name.
General Headers
Request Headers
Response Headers
CORS Headers
Caching Headers
About the HTTP Headers Lookup
This is a compact reference for the most common HTTP headers you will encounter when building or debugging web APIs. Each entry includes the header name, a short description, and an example value. Click any row to copy the header name to your clipboard.
Categories
- General — Headers that apply to both requests and responses (e.g.,
Connection,Date). - Request — Headers sent by the client (e.g.,
Authorization,User-Agent,Accept). - Response — Headers sent by the server (e.g.,
Content-Type,Set-Cookie,Server). - CORS — Cross-origin resource sharing headers (e.g.,
Access-Control-Allow-Origin). - Caching — Headers that control caching behavior (e.g.,
Cache-Control,ETag,Expires).
How to use
- Use the Filter input to search by header name or description.
- Click any row to copy the header name.
- Use the example value as a starting point for your own headers.
Frequently asked questions
Are all HTTP headers listed here? No — only the most commonly used ones. For the complete list, see the MDN HTTP Headers reference or the IANA registry.
What is the difference between Authorization and WWW-Authenticate? Authorization is sent by the client to authenticate; WWW-Authenticate is sent by the server (usually with a 401 response) to indicate the authentication scheme required.
Is the example value a real, valid value? Example values are illustrative. Some headers (like Authorization: Bearer <token>) require a real token; others (like Cache-Control: max-age=3600) can be used as-is.