If you have used the internet for a while, you may come across some type of errors displayed on the screen instead of a website or web page. Trying or refreshing the link several times might not show any favorable results. You may wonder how to solve the problem to see the website or web page that contains the information you needed. Luckily, there some status codes are available to identify the type of error that makes the problem. First, find the error status code, you notice that it is a three digit number.
The HTTP response codes indicate whether a specific HTTP request has been successfully completed or not. Responses can be classified into different groups: informational responses, successful responses, redirects, client errors, and servers errors. As I said, there are several types of responses are there, some important error status code with its definition, and a short description is explained here.
1xx Informational Responses
| Code | Definition | Info |
| 100 | continue | The server has received the request headers, and that the client should proceed to send the request body |
| 101 | Switching protocols | The requester has asked the server to switch protocols and the server is acknowledging that it will do so. |
| 102 | Processing (WebDAV) | The server has received and is processing the request, but no response is available yet. |
2xx Successful Responses
| Code | Definition | Info |
| 200 | OK | Standard response for successful HTTP requests. Most common code used to indicate success. |
| 201 | Created | The request has been fulfilled and resulted in a new resource being created. |
| 202 | Accepted | The request has been accepted for processing, but the processing has not been completed. |
| 203 | Non-Authoritative information | The server successfully processed the request but is returning information that may be from another source. |
| 204 | No content | The server successfully processed the request but is not returning any content. |
| 205 | Reset content | The server successfully processed the request but is not returning any content. This response requires that the requester reset the document view. |
| 206 | Partial content | The server is delivering only part of the resource due to a range header sent by the client. |
| 207 | Multi-Status (WebDAV) | Multiple resources in situations where multiple status codes might be appropriate. |
| 208 | Already reported (WebDAV) | Used inside a DAV: propstat response element to avoid enumerating the internal members of multiple bindings to the same collection repeatedly. |
| 226 | IM Used | The server has fulfilled a GET request for the resource. The response is a representation of the result of one or more instance-manipulations applied to the current instance. |
3xx Redirection Messages
| Code | Definition | Info |
| 300 | Multiple choices | This is for multiple options for the resource that the client may follow. |
| 301 | Moved Permanently | This and all future requests should be directed to a new permanent URL. |
| 302 | Found | The target resource resides temporarily under a different URL. |
| 303 | See other | The response to the request can be found under another URL using a GET method. |
| 304 | Not modified | The resource has not been modified since last requested. |
| 307 | Temporary redirect | The target resource resides temporarily under a different URL and the user agent must not change the request method used. |
| 308 | Permanent redirect | The target resource has been assigned a new permanent URL. |
4xx Client Error
| Code | Definition | Info |
| 400 | Bad request | The request cannot be fulfilled due to invalid syntax. |
| 401 | unauthorized | The request has not been applied because it lacks valid authentication credentials for the target resource. |
| 402 | Payment required | This is meant for digital cash or micropayment scheme. Now, reserved for future use. |
| 403 | Forbidden | The server understood the request, but refuse to respond to it. |
| 404 | Not Found | The requested resource could not be found now. The resource may be available again in the future. |
| 405 | Method not allowed | A request was made of a resource using a request method not supported by that resource (Get or POST method). |
| 406 | Not Acceptable | The requested resource is only capable of generating content not acceptable according to the Accept headers sent in the request. |
| 407 | Proxy Authentication Required | The client must first authenticate itself with the proxy. |
| 408 | Request Timeout | The server timed out waiting for the request. The server would like to shut down the unused connection. |
| 409 | Conflict | Shows that the request could not be processed because of conflict in the request |
| 410 | Gone | The resource requested is no longer available and will not be available again. |
| 411 | Length Required | The request did not specify the length of its content, which is required by the requested resource. |
| 412 | Precondition Failed | The server does not meet one of the preconditions that the requester put on the request. |
| 413 | Request Entity Too Large | The request is larger than the server is willing or able to process. |
| 414 | Request-URL Too Long | The URL provided was too long for the server to process. |
| 415 | Unsupported Media Type | The request contains a media type that the server does not support it. |
| 429 | Too Many Requests | The user has sent too many requests in a given amount of time. |
| 451 | Unavailable For Legal Reasons | Intended for resource access is denied for legal reasons like censorship or government-mandated blocked access. |
5xx Server Error
| Code | Definition | Info |
| 500 | Internal server error | The server encountered an unexpected problem that prevented it from fulfilling the request. |
| 501 | Not implemented | The server either does not recognize the request method, or it lacks the ability to fulfill the request. |
| 502 | Bad gateway | The server was acting as a gateway or proxy and received an invalid response from the upstream server. |
| 503 | Service unavailable | This a temporary state. The server is currently unavailable, may be due to overload or due to maintenance. |
| 504 | Gateway timeout | The server was acting as a gateway or proxy and did not receive a timely response from the upstream server. |
| 505 | HTTP version not supported | The server does not support the HTTP protocol version used in the request. |
| 506 | Variant also negotiates | The server has an internal configuration error. The resource is configured to engage in transparent content negotiation itself and is therefore not a proper end point in the negotiation process. |
| 507 | Insufficient storage | The server is unable to store the representation needed to successfully complete the request. |
| 508 | Loop detected | The server detected an infinite loop while processing the request. |
| 509 | Bandwidth limit exceeded | This error shows the site is receiving too much traffic than the host can allow. The more the visitors, the more the bandwidth consumed. |
| 511 | Network authentication required | The client needs to authenticate to gain network access. |
| 599 | Network connect timeout | A network connects timeout behind the proxy to a client in front of the proxy. |
This is an easy to reference database of error codes with their definition to assist to you to troubleshoot the common HTTP errors. You may notice that you may encounter most of the errors if you are a heavy internet user. The HTTP error 500 – internal server error is the most common error, which may due to the misconfiguration of the web server. We published a special article about how to fix HTTP 500 error. Error 403 – error may get if you try to obtain some forbidden directory of a website. The error 404 – not found is also the most common error that may grab our attention so many times when we are eagerly searching for something. The error may be due to a mistyped URL, or a broken link or the web admin removed that request page somewhere else or it may be deleted from the server. You can use the search functionality of a website to find the page if it is moved to a new location or the page link changed. The error code 401 status code is Unauthorized error. The user accessing the resource has not been authenticated or the user has not been authenticated correctly to access the resource. The 503 error code tells the Service Unavailable, that means the server may be overloaded or currently under maintenance. Don’t worry, this may happen frequently updated or in high traffic sites, you can access the resource after some time.
