In order to have a better understanding of HTTP codes, it pays to know their classifications. From 1 up to 5, each category has their own meaning.
An HTTP code starting with 1, 2, or 3 pertains to a granted request of access, or a fully functional request.
Those that begin with the number 4 means that an error occurred on the client’s side. Most HTTP errors in this category include 400, 401, 403, and 404.
Lastly, HTTP error codes with 5 as the first digit means an error on the server’s side. They come in the greatest numbers, spanning from 500 to 510.
The Most Common HTTP Errors Starting with the Digit 4
Although technically a client-side issue, website visitors usually encounter 4xx errors due to site-related issue. For instance, a malfunctioning link on a site’s home page will result in the very common 404 error.
400 Bad Request
Incorrect syntax in the request made by a user results in this error.
When visitors try to access a page that requires authentication, such as login credentials, and they enter incorrect information, they will encounter this error.
As the term already suggests, this means that the visitor does not have permission to access the file or contents of the URL.
404 Not Found
Aside from a malfunctioning link, this error also appears due to typos in the URL.
Monitoring these errors and finding out their causes will help you ensure your website remains up and running all the time. Fortunately, cPanel allows for the customization of these error pages, with its Error Pages interface.
The Most Common HTTP Errors Starting with the Digit 5
Despite apparently-valid visitor requests, HTTP error codes starting with 5 can still occur due to a server’s inability to fulfill the said request.
500 Internal Server Error
This occurs when an unexpected condition prohibits the server to fulfill a request.
501 Not Implemented
When a client chooses an HTTP method not supported by the server, this error occurs. In most cases, this indicates an outdated server is out of date.
502 Bad Gateway
Incorrect configuration of proxy servers have a lot to do with this 5xx error. Bad IP communication, malfunctioning firewall, and overloaded ISP can also lead to this error.
503 Service Unavailable
When a visitor makes a URL request for a site undergoing temporary overload or maintenance, this error code will appear.
504 Gateway Timeout
Slow Internet service or slow communication among servers cause this problem.
505 HTTP Version Not Supported
Incorrectly specified protocol will lead to the server refusing to support the HTTP protocol, ultimately resulting in this error code.
506 Variant Also Negotiates
Incorrectly configured server causes this HTTP error code.
507 Insufficient Storage
When the server runs out of free memory, this HTTP error will occur.
509 Bandwidth Limit Exceeded
System administrators impose certain limitations when it comes to bandwidth usage. When a user reaches this limit, the 509 error will appear.
510 Not Extended
When an HTTP request comes attached with an extension the web server does not support, the user will encounter this error.
The fastest resolution to these problems is to have your system administrator check and fix them.