List of HTML Server Codes

HTML Error codes:

• 200 – OK
  Successful transmission. This is not an error. The file you requested was found –– here it is.
• 201 – Created
  The request has been fulfilled and resulted in a new resource being created. The newly created resource can be referenced by the URL(s) returned in the URL – header field of the response. The most specific URL for the resource will be given by a Location header field.
• 202 – Accepted
  The request has been accepted for processing, but the processing has not yet completed.
• 203 – Non – Authoritative Information
  The returned META information in the Entity – Header is not the definitive set as available from the origin server, but is gathered from a local or third – party copy.
• 204 – No Content
  The server has fulfilled the request, but there is no new information to send back.
• 206 – Partial Content
  You requested a range of bytes in the file, and here they are. This is new in HTTP/1.1

Here are the most common 300 Error Codes:

• 300 – Multiple Choices
  The requested source is available at one or more locations and a preferred location could not be determined via content negotiation.
• 301 – Moved Permanently
  The requested resource has been assigned a new permanent URL and any future references to this resource should be done using one of the returned URLs.
• 302 – Moved
  Temporarily – The requested resource resides temporarily under a new URL. Redirection to a new URL should be provided. This is not an error, most browsers invisibly fetch the new page upon seeing this result.
• 303 – See Other
  The requested resource resides under a different URL and should be accessed using a Get method on that resource.
• 304 – Not Modified
  If the client has performed a conditional GET request and access is allowed; however, the document has not been modified since the date and time specified in the If – Modified – Since field – then the server responds with this status code and does not send an Entity – Body to the client. If it also says, "Use local copy." This means that the copy of the file on the web server is not more recent than the copy which your web browser or proxy server has cached locally, so there's no point in sending the file again. This is not an error.
• Other 300's
  Redirected requests are those with other codes in the 300s. The most common cause of these requests is that the user has incorrectly requested a directory name without the trailing slash. The server replies with a redirection ("you probably mean the following") and the user then makes a second connection to get the correct document (although usually the browser does it automatically without the user's intervention or knowledge).
  If you have a large number of 300 level result codes in your logs, you have probably specified links without the trailing "/" (slash).

Here are the most common 400 Error Codes:

• 400 – Bad
  Request – The request could not be understood by the server because the syntax was incorrect. A bad request was made by the client.
• 401 – Unauthorized
  The request requires user authentication. The response must include a WWW – Authenticate header field containing a challenge applicable to the requested source. The user asked for a document but did not provide a valid username or password.
• 402 – Payment
  Required – This code is not currently supported, but is reserved for future use.
• 403 – Forbidden
  The server understood the request but is refusing to perform the request because of an unspecified reason. Access is explicitly denied to this document. This might happen because the web server doesn't have read permission for the file you're requesting.
• 404 – Not Found
  The server has not found anything matching the requested URL. 04 errors are the result of requests for pages which do not exist, and can come from a mistyped URL, a bookmark which points to a file no longer there, search engines looking for a robots.txt (which is used to mark pages you don't want indexed by search engines), people guessing filenames, bad links from your site or other sites, etc.
• 405 – Method Not
  Allowed – The method specified in the request line is not allowed for the resource identified by the requested URL.
• 406 – None Acceptable
  The server has found a resource matching the request URL, but not one that satisfies the conditions identified by the Accept and Accept – Encoding request headers.
• 407 – Proxy
  Authentication Required – This code is reserved for future use. It is similar to 401 (Unauthorized) but indicates that the client must first authenticate itself with a proxy. HTTP/1.0 does not provide a means for proxy authentication.
• 408 – Request Timeout
  The client did not produce a request within the time the server was prepared to wait.
• 409 – Conflict
  The request could not be completed due to a conflict with the current state of the resource.
• 410 – Gone
  Therequested resource is no longer available at the server and no forwarding address is known.
• 411 – Authorization Refused
  The request credentials provided by the client were rejected by the server or insufficient to grant authorization to access the resource.

Here are the most common 500 (and beyond) Error Codes:

• 500 – Internal Server Error
  The server encountered an unexpected condition that prevented it from filling the request. There is usually nothing that can be done from the browser end to fix this error. The server administrator will probably need to check the server's error log to see what happened. This is often the error message for Frontpage for a CGI script which has not been properly coded.
• 501 – Not Implemented
  The server does not support the functionality required to fulfill the request. Application method (either GET or POST) is not implemented.
• 502 – Bad Gateway
  The server received an invalid response from the gateway or upstream server it accessed in attempting to fulfill the request.
• 503 – Service Unavailable
  The server is currently unable to handle the request due to a temporary overloading or maintenance of the server. Server is out of resources.
• 504 – Gateway Timeout
  The server did not receive a timely response from the gateway or upstream server it accessed in attempting to complete the request.
• 8181 –
  Certificate has expired (secure server only).