Status codes returned by a server, to indicate how a HTTP request has been handled.

Responses are grouped in five classes:

  • 100-199 are Informational responses
  • 200-299 are Successful responses
  • 300–399 are Redirection messages
  • 400-499 are Client error responses
  • 500-599 are Server error responses

Example:

HTTP/2 301 Moved Permanently
Location: https://northrook.com/new-address

Need more details? Read the Mozilla Developers resource here.