The Internet Assigned Numbers Authority (IANA) maintains the official registry of HTTP status codes.

Microsoft Internet Information Services (IIS) sometimes uses additional decimal sub-codes for more specific information, however, these sub-codes only appear in the response payload and in the documentation, not in the place of an actual HTTP status code.

All HTTP response status codes are separated into five classes (or categories). The first digit of the status code defines the class of response. The last two digits do not have any class or categorization role. There are five values for the first digit:

  • 1xx (Informational): The request was received, continuing process
  • 2xx (Successful): The request was successfully received, understood, and accepted
  • 3xx (Redirection): Further action needs to be taken in order to complete the request
  • 4xx (Client Error): The request contains bad syntax or cannot be fulfilled
  • 5xx (Server Error): The server failed to fulfill an apparently valid request

This is a list of Hypertext Transfer Protocol (HTTP) response status codes. Status codes are issued by a server in response to a client’s request made to the server. It includes codes from IETF Request for Comments (RFCs), other specifications, and some additional codes used in some common applications of the Hypertext Transfer Protocol (HTTP).

The first digit of the status code specifies one of five standard classes of responses. The message phrases shown are typical, but any human-readable alternative may be provided. Unless otherwise stated, the status code is part of the HTTP/1.1 standard.

1xx Informational

2xx Success

3xx Redirection

4xx Client Error

  • 400 Bad Request
  • 401 Unauthorized
  • 402 Payment Required
  • 403 Forbidden
  • 404 Not Found
  • 405 Method Not Allowed
  • 406 Not Acceptable
  • 407 Proxy Authentication Required
  • 408 Request Timeout
  • 409 Conflict
  • 410 Gone
  • 411 Length Required
  • 412 Precondition Failed
  • 413 Request Entity Too Large
  • 414 Request-URI Too Long
  • 415 Unsupported Media Type
  • 416 Requested Range Not Satisfiable
  • 417 Expectation Failed
  • 418 I’m a teapot (RFC 2324)
  • 420 Enhance Your Calm (Twitter)
  • 422 Unprocessable Entity (WebDAV)
  • 423 Locked (WebDAV)
  • 424 Failed Dependency (WebDAV)
  • 425 Reserved for WebDAV
  • 426 Upgrade Required
  • 428 Precondition Required
  • 429 Too Many Requests
  • 431 Request Header Fields Too Large
  • 444 No Response (Nginx)
  • 449 Retry With (Microsoft)
  • 450 Blocked by Windows Parental Controls (Microsoft)
  • 451 Unavailable For Legal Reasons
  • 499 Client Closed Request (Nginx)

5xx Server Error

  • 500 Internal Server Error
  • 501 Not Implemented
  • 502 Bad Gateway
  • 503 Service Unavailable
  • 504 Gateway Timeout
  • 505 HTTP Version Not Supported
  • 506 Variant Also Negotiates (Experimental)
  • 507 Insufficient Storage (WebDAV)
  • 508 Loop Detected (WebDAV)
  • 509 Bandwidth Limit Exceeded (Apache)
  • 510 Not Extended
  • 511 Network Authentication Required

 

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