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.


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:

List of HTTP status codes

  • 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

HTTP STATUS CODES – 1xx: Information

Message Description
100 Continue Only a part of the request has been received by the server, but as long as it has not been rejected, the client should continue with the request.
101 Switching Protocols The server switches protocol.

102 Processing , 103 Early Hints

HTTP STATUS CODES – 2xx: Successful

Message Description
200 OK The request is OK.
201 Created The request is complete, and a new resource is created .
202 Accepted The request is accepted for processing, but the processing is not complete.
203 Non-authoritative Information The information in the entity header is from a local or third-party copy, not from the original server.
204 No Content A status code and a header are given in the response, but there is no entity-body in the reply.
205 Reset Content The browser should clear the form used for this transaction for additional input.
206 Partial Content The server is returning partial data of the size requested. Used in response to a request specifying a Range header. The server must specify the range included in the response with the Content-Range header.

207 Multi-Status, 208 Already Reported, 226 IM Used

HTTP STATUS CODES – 3xx: Redirection

Message Description
300 Multiple Choices A link list. The user can select a link and go to that location. Maximum five addresses  .
301 Moved Permanently The requested page has moved to a new url .
302 Found The requested page has moved temporarily to a new url .
303 See Other The requested page can be found under a different url .
304 Not Modified This is the response code to an If-Modified-Since or If-None-Match header, where the URL has not been modified since the specified date.
305 Use Proxy The requested URL must be accessed through the proxy mentioned in the Location header.
306 Unused This code was used in a previous version. It is no longer used, but the code is reserved.
307 Temporary Redirect The requested page has moved temporarily to a new url.

308 Permanent Redirect

HTTP STATUS CODES – 4xx: Client Error

Message Description
400 Bad Request The server did not understand the request.
401 Unauthorized The requested page needs a username and a password.
402 Payment Required You can not use this code yet.
403 Forbidden Access is forbidden to the requested page.
404 Not Found The server can not find the requested page.
405 Method Not Allowed The method specified in the request is not allowed.
406 Not Acceptable The server can only generate a response that is not accepted by the client.
407 Proxy Authentication Required You must authenticate with a proxy server before this request can be served.
408 Request Timeout The request took longer than the server was prepared to wait.
409 Conflict The request could not be completed because of a conflict.
410 Gone The requested page is no longer available .
411 Length Required The “Content-Length” is not defined. The server will not accept the request without it .
412 Precondition Failed The pre condition given in the request evaluated to false by the server.
413 Request Entity Too Large The server will not accept the request, because the request entity is too large.
414 Request-url Too Long The server will not accept the request, because the url is too long. Occurs when you convert a “post” request to a “get” request with a long query information .
415 Unsupported Media Type The server will not accept the request, because the mediatype is not supported .
416 Requested Range Not Satisfiable The requested byte range is not available and is out of bounds.
417 Expectation Failed The expectation given in an Expect request-header field could not be met by this server.

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

HTTP STATUS CODES – 5xx: Server Error

Message Description
500 Internal Server Error The request was not completed. The server met an unexpected condition.
501 Not Implemented The request was not completed. The server did not support the functionality required.
502 Bad Gateway The request was not completed. The server received an invalid response from the upstream server.
503 Service Unavailable The request was not completed. The server is temporarily overloading or down.
504 Gateway Timeout The gateway has timed out.
505 HTTP Version Not Supported The server does not support the “http protocol” version.

506 Variant Also Negotiates, 507 Insufficient Storage, 508 Loop Detected, 510 Not Extended, 511 Network Authentication Required.


The following codes are not specified by any standard.

103 Checkpoint
Used in the resumable requests proposal to resume aborted PUT or POST requests.
218 This is fine (Apache Web Server)
Used as a catch-all error condition for allowing response bodies to flow through Apache when ProxyErrorOverride is enabled. When ProxyErrorOverride is enabled in Apache, response bodies that contain a status code of 4xx or 5xx are automatically discarded by Apache in favor of a generic response or a custom response specified by the ErrorDocument directive.
419 Page Expired (Laravel Framework)
Used by the Laravel Framework when a CSRF Token is missing or expired.
420 Method Failure (Spring Framework)
A deprecated response used by the Spring Framework when a method has failed.
420 Enhance Your Calm (Twitter)
Returned by version 1 of the Twitter Search and Trends API when the client is being rate limited; versions 1.1 and later use the 429 Too Many Requests response code instead. The phrase “Enhance your calm” comes from the 1993 movie Demolition Man, and its association with this number is likely a reference to cannabis.
430 Request Header Fields Too Large (Shopify)
Used by Shopify, instead of the 429 Too Many Requests response code, when too many URLs are requested within a certain time frame.
450 Blocked by Windows Parental Controls (Microsoft)
The Microsoft extension code indicated when Windows Parental Controls are turned on and are blocking access to the requested webpage.
498 Invalid Token (Esri)
Returned by ArcGIS for Server. Code 498 indicates an expired or otherwise invalid token.
499 Token Required (Esri)
Returned by ArcGIS for Server. Code 499 indicates that a token is required but was not submitted.
509 Bandwidth Limit Exceeded (Apache Web Server/cPanel)
The server has exceeded the bandwidth specified by the server administrator; this is often used by shared hosting providers to limit the bandwidth of customers.
526 Invalid SSL Certificate
Used by Cloudflare and Cloud Foundry’s gorouter to indicate failure to validate the SSL/TLS certificate that the origin server presented.
529 Site is overloaded
Used by Qualys in the SSLLabs server testing API to signal that the site can’t process the request.
530 Site is frozen
Used by the Pantheon web platform to indicate a site that has been frozen due to inactivity.
598 (Informal convention) Network read timeout error
Used by some HTTP proxies to signal a network read timeout behind the proxy to a client in front of the proxy.

Internet Information Services

Microsoft’s Internet Information Services (IIS) web server expands the 4xx error space to signal errors with the client’s request.

440 Login Time-out
The client’s session has expired and must log in again.
449 Retry With
The server cannot honour the request because the user has not provided the required information.
451 Redirect
Used in Exchange ActiveSync when either a more efficient server is available or the server cannot access the users’ mailbox. The client is expected to re-run the HTTP AutoDiscover operation to find a more appropriate server.

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
Used internally to instruct the server to return no information to the client and close the connection immediately.
494 Request header too large
Client sent too large request or too long header line.
495 SSL Certificate Error
An expansion of the 400 Bad Request response code, used when the client has provided an invalid client certificate.
496 SSL Certificate Required
An expansion of the 400 Bad Request response code, used when a client certificate is required but not provided.
497 HTTP Request Sent to HTTPS Port
An expansion of the 400 Bad Request response code, used when the client has made a HTTP request to a port listening for HTTPS requests.
499 Client Closed Request
Used when the client has closed the request before the server could send a response.


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
The origin server returned an empty, unknown, or unexplained response to Cloudflare.
521 Web Server Is Down
The origin server has refused the connection from Cloudflare.
522 Connection Timed Out
Cloudflare could not negotiate a TCP handshake with the origin server.
523 Origin Is Unreachable
Cloudflare could not reach the origin server; for example, if the DNS records for the origin server are incorrect.
524 A Timeout Occurred
Cloudflare was able to complete a TCP connection to the origin server, but did not receive a timely HTTP response.
525 SSL Handshake Failed
Cloudflare could not negotiate a SSL/TLS handshake with the origin server.
526 Invalid SSL Certificate
Cloudflare could not validate the SSL certificate on the origin web server.
527 Railgun Error
Error 527 indicates an interrupted connection between Cloudflare and the origin server’s Railgun server.
Error 530 is returned along with a 1xxx error.

AWS Elastic Load Balancer

Amazon’s Elastic Load Balancing adds a few custom 4xx return codes


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.


The load balancer received an X-Forwarded-For request header with more than 30 IP addresses.

References: Wikipedia, Tutorials Point


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