This is a list of Hypertext Transfer Protocol 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, other specifications, and some additional codes used in some common applications of the 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. The Internet Assigned Numbers Authority maintains the official registry of HTTP status codes. All HTTP response status codes are separated into five classes or categories. The first digit of the status code defines the class of response, while the last two digits do not have any classifying or categorization role. There are five classes defined by the standard:
1xx informational response – 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 fulfil an apparently valid request
1xx Informational response
An informational response indicates that the request was received and understood. It is issued on a provisional basis while request processing continues. It alerts the client to wait for a final response. The message consists only of the status line and optional header fields, and is terminated by an empty line. As the HTTP/1.0 standard did not define any 1xx status codes, servers must not send a 1xx response to an HTTP/1.0 compliant client except under experimental conditions. ;100 Continue ;101 Switching Protocols ;102 Processing ;103 Early Hints
2xx Success
This class of status codes indicates the action requested by the client was received, understood, and accepted. ;200 OK ;201 Created ;202 Accepted ;203 Non-Authoritative Information ;204 No Content ;205 Reset Content ;206 Partial Content ;207 Multi-Status ;208 Already Reported ;226 IM Used
3xx Redirection
This class of status code indicates the client must take additional action to complete the request. Many of these status codes are used in URL redirection. A user agent may carry out the additional action with no user interaction only if the method used in the second request is GET or HEAD. A user agent may automatically redirect a request. A user agent should detect and intervene to prevent cyclical redirects. ;300 Multiple Choices ;301 Moved Permanently ;302 Found ;303 See Other ;304 Not Modified ;305 Use Proxy ;306 Switch Proxy ;307 Temporary Redirect ;308 Permanent Redirect
4xx Client errors
This class of status code is intended for situations in which the error seems to have been caused by the client. Except when responding to a HEAD request, the server should include an entity containing an explanation of the error situation, and whether it is a temporary or permanent condition. These status codes are applicable to any request method. User agents should display any included entity to the user. ;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 Payload Too Large ;414 URI Too Long ;415 Unsupported Media Type ;416 Range Not Satisfiable ;417 Expectation Failed ;418 I'm a teapot ;421 Misdirected Request ;422 Unprocessable Entity ;423 Locked ;424 Failed Dependency ;425 Too Early ;426 Upgrade Required ;428 Precondition Required ;429 Too Many Requests ;431 Request Header Fields Too Large ;451 Unavailable For Legal Reasons
5xx Server errors
The server failed to fulfill a request. Response status codes beginning with the digit "5" indicate cases in which the server is aware that it has encountered an error or is otherwise incapable of performing the request. Except when responding to a HEAD request, the server should include an entity containing an explanation of the error situation, and indicate whether it is a temporary or permanent condition. Likewise, user agents should display any included entity to the user. These response codes are applicable to any request method. ;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 ;507 Insufficient Storage ;508 Loop Detected ;510 Not Extended ;511 Network Authentication Required
Unofficial codes
The following codes are not specified by any standard. ;103 Checkpoint ;218 This is fine ;419 Page Expired ;420 Method Failure ;420 Enhance Your Calm ;430 Request Header Fields Too Large ;450 Blocked by Windows Parental Controls ;498 Invalid Token ;499 Token Required ;509 Bandwidth Limit Exceeded ;526 Invalid SSL Certificate ;529 Site is overloaded ;530 Site is frozen ;598 Network read timeout error
Microsoft's Internet Information Servicesweb server expands the 4xx error space to signal errors with the client's request. ;440 Login Time-out ;449 Retry With ;451 Redirect IIS sometimes uses additional decimal sub-codes for more specific information, however these sub-codes only appear in the response payload and in documentation, not in the place of an actual HTTP status code.
The nginx web server software expands the 4xx error space to signal issues with the client's request. ;444 No Response ;494 Request header too large ;495 SSL Certificate Error ;496 SSL Certificate Required ;497 HTTP Request Sent to HTTPS Port ;499 Client Closed Request
Cloudflare
's reverse proxy service expands the 5xx series of errors space to signal issues with the origin server. ;520 Web Server Returned an Unknown Error ;521 Web Server Is Down ;522 Connection Timed Out ;523 Origin Is Unreachable ;524 A Timeout Occurred ;525 SSL Handshake Failed ;526 Invalid SSL Certificate ;527 Railgun Error ;530
AWS Elastic Load Balancer
's Elastic Load Balancing adds a few custom 4xx return codes 460 Client closed the connection with the load balancer before the idle timeout period elapsed. Typically when client timeout is sooner than the Elastic Load Balancer's timeout. 463 The load balancer received an X-Forwarded-For request header with more than 30 IP addresses.
