HTTP Messages

Updated 17 Sep 2026

•
What it is
- •
  requests communicate what the client wants; responses communicate the server's result and any returned representation
•
HTTP/1.1 request
- •
  request line: method, request target, version
- •
  headers
- •
  blank line
- •
  optional body
•
HTTP/1.1 response
- •
  status line: version and status code, conventionally followed by a reason phrase
- •
  headers
- •
  blank line
- •
  body when permitted
•
Useful statuses
- •
  200 — successful response
- •
  301 — permanent redirect; Location identifies the destination
- •
  304 — a conditional retrieval can reuse its stored representation
- •
  400 — bad request
- •
  404 — resource not found
- •
  405 — method not allowed
- •
  406 — no acceptable representation supplied
- •
  500 — server error
•
Caution
- •
  200 does not prove that the client can decode or correctly interpret the returned content
•
Related
- •
  HTTP Headers
- •
  HTTP Methods

Linked references 3