HTTP status codes | Server Error Responses

Last Updated : 15 Jul, 2020

HTTP status codes is a conversation between your browser and the site server. The server gives responses to the browser’s request in the form of a three-digit code known as HTTP status codes. Categories of HTTP status codes are.

Informational responses (100–199)
Successful responses (200–299)
Redirects (300–399)
Client errors (400–499)
Server errors (500–599)

Server Error Responses: Server error response occurs when the server fails to fulfill the request of the visitor.

500 Internal Server Error: 500 Internal Server Error is a common error message that occurs when the server meets an unexpected situation and it doesn’t know how to handle it.
Status:
```
500 Internal Server Error
```
501 Not Implemented: 501 Not Implemented occurs when the requested method is not supported by the server. The server either does not perceive the request or it comes up short on the capacity to fulfill the request. GET and HEAD are the only methods that the server support.
Status:
```
501 Not Implemented
```
502 Bad Gateway: 502 Bad Gateway occurs when the server is working as a gateway and it receives an invalid response from the upstream server.
Status:
```
502 Bad Gateway
```
503 Service Unavailable: 503 Service Unavailable occurs when the server is unable to handle the requests (the server is temporarily overloading or down).
Status:
```
503 Service Unavailable
```
504 Gateway Timeout: 504 Gateway Timeout occurs when the server is acting as a gateway and did not get a response from the upstream server on time.
Status:
```
504 Gateway Timeout
```
505 HTTP Version Not Supported: 505 HTTP Version Not Supported occurs when the HTTP protocol version used in the request is not supported by the server.
Status:
```
505 HTTP Version Not Supported 
```
506 Variant Also Negotiated: 506 Variant Also Negotiated occurs when there is an internal configuration error in the server.
Status:
```
506 Variant Also Negotiated
```
507 Insufficient Storage: 507 Insufficient Storage occurs when the server is unable to store or execute the (PUT or POST) operation that is required to complete the request successfully due to the large size of the operation.
Status:
```
507 Insufficient Storage
```
508 Loop Detected: 508 Loop Detected occurs when an infinite loop is detected by the server while processing the request. The request is terminated by the server.
Status:
```
508 Loop Detected
```
510 Not Extended: 509 Not Extended occurs when there are no further resources(extensions) for the server to complete the required request.
Status:
```
510 Not Extended
```
511 Network Authentication Required: The 511 Network Authentication Required occurs when the visitors need to authenticate in order to gain network access.
Status:
```
511 Network Authentication Required
```