Base de connaissances

HTTP status codes

The HTTP protocol describes the HTTP status codes that the web server sends in response to requests from the web browser.

There are several types of status codes, with only the last two types indicating an error message. Arranged according to the web specification, they look like this:

1xx: Information
2xx: Successful
3xx: Redirection
4xx: Client error
5xx: Server Error

100 Continue

This status code does not mean an error, but a confirmation that everything is "OK".
200 OK

When the web server responds to a request from the web browser, it displays this with a status code of 200 OK.
201 Created

Indicates that a new resource has been successfully created on the server.
202 Accepted

The request has been accepted, but the execution is not completed, the action will continue asynchronously.
204 No Content

The request was completed successfully, but the requested resource is empty (no content, zero length).
206 Partial Content

The request is aborted before it is complete - the message is given by some programs, usually when the user is tired of waiting for the opening of one file and moves on to the next.
300 Multiple Choices

The request is unclear and it is necessary to specify which of the many resources is requested.
301 Moved Permanently and 302 Found

The 301 code indicates that the redirection is permanent and in the future the client should only use the new web address. The 302 code indicates to web clients that the new resource address is temporary, ie to use the old web address in the future.
304 Not Modified

The message indicates that the client copy of the requested information is up-to-date and therefore there is no need to download the resource from the server again.
400 Bad Request

Due to poor syntax, the request cannot be understood by the server. The customer must repeat the request only after modifying it.
401 Unauthorized

Identification is required to access the resources. The message means that you do not have permission to access the requested information. Contact your server administrator if you think your access to resources should be allowed.
403 Forbidden

Access denied. The server understands the request but refuses to fulfill it. Some possible reasons for this message are: trying to access a directory (folder) that does not have an index page, such as index.html; attempt to access password-protected resources when entering the wrong password; attempt to access a Secure Sockets Layer (SSL) secured page; denied access through your IP address, etc.
404 Not Found

The server could not find the requested resource. A possible reason for this is an incorrect URL or that the resource does not exist. If the error persists, it is advisable to contact the site administrator.
405 Method Not Allowed

The method by which the request for access to the resource was made is not allowed.
406 Not Acceptable

Unacceptable application.
407 Proxy Authentication Required

You need to log in through a proxy server to receive the requested resource.
408 Request Time-Out

Time-out for the request.
409 Conflict

There is an internal contradiction, due to which the requested resource cannot be accessed.
410 Gone

The requested resource is not available on the server and there is no reference to any new location.
413 Request Entity Too Large

The request is too long.
414 Request-URL Too Large

The request URL is too long.
415 Unsupported Media Type

The server does not support the requested resource type.
500 Server Error

The server is unable to execute the request due to an internal server error. You should try again or contact your server administrator.
501 Not Implemented

The request requires a feature that is not installed on the server.
502 Bad Gateway

Acting as a gateway or proxy, the server receives an invalid response from the source server that must execute the request.
503 Out of Resources

The request is temporarily unfulfilled, most likely due to exhausted resources.
504 Gateway Time-Out

The connection to the original content source, the web server, has not been established. This message can be received when a proxy service (Cloudflare) is activated for the site.
505 HTTP Version not supported

The request uses an unsupported version of HTTP.