Most Common HTTP Error Codes List Explained

[Ishaan]

In this article, we have explained the most common HTTP errors codes that occurs most of the times when browsing a website.

Surely at least once you must have seen the Error 404 Page Not Found (This page cannot be displayed because it does not exist or is unavailable) and other such errors. What does these errors stand for?

First of all you must know, what is the Apache server: A site that uses the HTTP or HTTPS (secure http) to provide access to sites. The overwhelming majority of the planet earth servers use the Apache server, either on Linux or Windows.

Finally, according to the specification of the Apache Foundation (which controls the Apache Foundation), the HTTP error codes start at 400 and end at 510. The 4xx errors are errors normally expected in the users accessing the server and 5xx errors are expected on the server. Although, this is the official specification, there is room for mistakes in practice, where codes 5xx may be due to problems of the client that sends files or systems that do not confirm to the specifications of the server.

We have listed below here the most common mistakes by their numbers (each of these errors are identified by a unique number). Not all numbers are used by the Apache Foundation, while others are being removed in later versions of Apache 2.x.

4xx : Client Errors

Error 400 Bad Request : It is an error usually caused by the requisition of some traffic between your connection and the server. Some error occurred on the HTTP protocol and he was denied by the server. Usually clearing the cache on your browser to force the update with the CTRL + F5 or reconnecting solves the problem. Often the error is associated with those who access the site and not the server, because it is he who finds all his requests to identify possible problems.

Error 401 Unauthorized : Access was not granted because a password is required for access or because the arguments (or credentials) required for access were not informed. In some cases the browser used does not understand what those credentials and can not access the requested URL.

Error 402 Payment Required : Error being removed by the Apache Foundation.

Error 403 Forbidden : The server access is denied for any reason. In general, it is because the user is not authorized to open a directory or list your site.

Error 404 Not found : Usually caused by an attempt to access a directory or file does not exist on your site.

Error 407 Proxy Authentication Required : The connection should have been done through a proxy, but it was not generating that error.

Error 408 Request Timeout : Any request made by those who access the site was not seen at the expected time and the server breaks the connection, or simply lost. Often this problem is associated with the connection of who tries to access the site. The problem may occur more frequently on servers that have mirror or when it is overloaded.

HTTP Error 410 Gone : This error usually occurs with a site that has migrated from one web server hosting service to another. This occurs when the person accessing your site is redirected to the old hosting service. There website no longer exists, then the old server returns the 410 error, but can also return a 404 error, which may confuse the account owner and technical support. In general the error 410 disappears automatically according to the propagation of the new DNS provided by the new hosting service.

Error 411 Length Required : For simplicity, is a feature of HTTP for transport of information of that protocol. Almost always this problem comes from the user accessing the site, but specifically in your browser. Usually the problem occurs when there is an overload of data on the user's Internet connection.

Error 412 Precondition Failed : Usually the problem is, the user who accesses the site when, the browser requires a state condition that does not exist on the server. For example it is trying to access a site via HTTPS (secure HTTP) and the site does not support this protocol.

Error 413 Request Entity Too Large : Often the error comes from the user accessing the server. The error occurs when the user sends more data than expected by the server. This stems from several causes but the most common is when the server has a limit, for instance, 10MB per upload and the user sends more than 10Mb. Reinforcing "10Mb" was just an example.

Error 414 Request URL Too Large : Most servers accept anything from 2048 up to 4096 characters in a URL (address). When you exceed this limit, the server returns a 414 error. The limit must exist especially to prevent injection of malicious code and also to prevent corruption of the packages when working with quantities not anticipated by the original specification of Apache.

Error 415 Unsupported Media Type : This error occurs when some type of service is not available on the server and the user is trying to use it in your hosting account. Examples of services: PHP, some types of streaming and other services that require specific libraries to function and that are not installed or not configured on the server.

Error 422 Unprocessed Entity : Some resource (usually multimedia) that although recognized by the server for some reason can not be processed. Usually if the error is intermittent, because there is problem in the media that the user added.

5xx : Server Errors

Error 500 Internal Server Error : This error occurs when a logical state of a directory or file is not in accordance with the server settings, ie, not being satisfied by the server. Although the cause may be at various events, the most common is when a user sets up chmod 644 to files or directories to over 755. The servers use so iLax SU PHP, where any of those specified above chmod 500 error by generating a security issue.

Error 501 Not Implemented : This error occurs when the user accesses order something that exists within the HTTP protocol, but that is not implemented on the server that it tries to access.

Error 502 Bad Gateway : This error occurs when there is some data service intermediate between the user and server access. Typically the service that causes the most common failure is a proxy between the user and the server. There is some mismatch between what the client asks the proxy asks the server and vice versa.

Error 503 Service Unavailable : Unlike the 415 error, the service is available on the server but is temporarily off the air (because of maintenance, for example) or is overloaded (at times of peak usage of server resources, for example). In this case, the problem usually resolves without any change in any party (user or server).

Error 506 Variant Also Varies : It may be a cache problem or server or user modules Apache server causes a problem in the traffic of specific packages. The problem should be evaluated on the server.

Error 507 Insufficient Storage : There is space available on the client to perform some action requested by the site (ex: a user accessing the site and using some kind of resource that consume memory or disk space).