Detailed Explanation of HTTP Server Status/Error Codes

When a user wants to connect to a website via a computer, the server of the related web site sends some status codes. These status codes are named as HTTP Server Status/Error Codes and give the current status or error state of a server. These codes give information about the server and inform the user if there is an error on request headers or response headers. Status codes are informational codes and there isn’t any effect to browse the related website, on the other hand as the name implies error codes are codes that inform the user the type of error. Users can’t reach a website if there is an error code on the server. If you are a system administrator these error codes give hints about the error type and you can decide what actions need to be taken to fix the problem.

HTTP Server Status/Error Codes can be divided into 5 subcategories;

• 1xx: Informational Codes
• 2xx: Success Codes
• 3xx: Redirection Codes
• 4XX: Client-Side Error Codes
• 5xx: Server Side Error Codes

1xx: Informational Codes

Informational Codes shows that a request has been made to the server and the server acknowledged the request. It shows that users needs to wait for some time to see the final status.

100: Continue
101: Switching Protocols
102: Processing
103: Early Hints

2xx: Success Codes

Success Codes shows that the request is processed successfully.

200: OK
201: Created
202: Accepted
203: Non-Authorative Information
204: No Content
205: Reset Content
206: Partial Content
207: Multi-Status
208: Already Reported
209: IM Used

3xx: Redirection Codes

Redirection Codes show that the request will be redirected temporarily or permanently to an another website or web page or the content is completely removed. These status codes also gives information about proxies.

300: Multiple Choices
301: Moved Permanently
302: Found “Previously Moved Temporarily”
303: See Other
304: Not Modified
305: Use Proxy
306: Switch Proxy
307: Temporary Redirect
308: Permanent Redirect

4xx: Client-Side Error Codes

Client-Side Error Codes shows that the request contains some errors and the server will not be able to process the request. A user could be trying to see an unauthorized, non-existent or prohibited content. Along with that it shows that the request is taking too long or too many requests have been sent.

400: Bad Request
401: Unauthorized
402: Payment Required
403: Forbidden

404: Not Found
405: Method Not Allowed
406: Not Acceptable
407: Proxy Authentication Required
408: Request Timeout
409: Conflict
410: Gone
411: Length Required
412: Precondition Failed
413: Payload Too Large
414: URI Too Long
415: Unsupported Media Type
416: Range Not Satisfiable
417: Expectation Failed
421: Misdirected Request
422: Unprocessable Entity
423: Locked
424: Failed Dependency
425: Too Early
426: Upgrade Required
428: Precondition Required
429: Too Many Requests
431: Request Header Fields Too Large
451: Unavailable For Legal Reasons

5xx: Server Side Error Codes

Server Side Error Codes show that the request couldn’t be processed because of some error or insufficiency on the server.

500: Internal Server Error
501: Not Implemented
502: Bad Gateway
503: Service Unavailable
504: Gateway Timeout
505: HTTP Version Not Supported
506: Variant Also Negotiates
507: Insufficient Storage
508: Loop Detected
510: Not Extended
511: Network Authentication Required