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Infrastructure & Networking

What is HTTP Status Codes?

What is HTTP Status Codes?

HTTP response status codes, also known as status codes, are numerical codes that are generated by a server in response to a request made by a client on the browser side. The purpose of status codes is to facilitate efficient and clear communication regarding the server's handling and response to the client's request.

The codes provided encompass codes from IETF Requests for Comments (RFCs), other specifications, and additional codes commonly utilized in HTTP applications.

1xx Informational

It reflects the request's receipt and comprehension. It is temporary while request processing proceeds. It tells the client to wait for a reply. The message has merely the status line and optional header fields, ending with an empty line.

100 Continue

101 Switching Protocols

102 Processing (WebDAV)

2xx Success

It shows the client's activity was received, comprehended, and accepted. This implies that the client's request was valid and that the server fulfilled its obligation.

200 OK

201 Created

202 Accepted

203 Non-Authoritative Information

204 No Content

205 Reset Content

206 Partial Content

207 Multi-Status (WebDAV)

208 Already Reported (WebDAV)

226 IM Used

3xx Redirection

It suggests the customer may take more action to complete the request. That additional step usually redirects the user to another URL. URL redirection uses many of these status codes.

300 Multiple Choices

301 Moved Permanently

302 Found

303 See Other

304 Not Modified

305 Use Proxy

306 (Unused)

307 Temporary Redirect

308 Permanent Redirect (experimental)

4xx Client Error

If the request falls into this category, it's because the client has made a mistake. It's possible that the request has syntactic errors, lacks proper authorization, etc. Except when replying to a HEAD request, the server must include an object detailing the issue and whether or not it is transitory.

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 Request Entity Too Large

414 Request-URI Too Long

415 Unsupported Media Type

416 Requested Range Not Satisfiable

417 Expectation Failed

418 I'm a teapot (RFC 2324)

420 Enhance Your Calm (Twitter)

422 Unprocessable Entity (WebDAV)

423 Locked (WebDAV)

424 Failed Dependency (WebDAV)

425 Reserved for WebDAV

426 Upgrade Required

428 Precondition Required

429 Too Many Requests

431 Request Header Fields Too Large

444 No Response (Nginx)

449 Retry With (Microsoft)

450 Blocked by Windows Parental Controls (Microsoft)

451 Unavailable For Legal Reasons

499 Client Closed Request (Nginx)

5xx Server Error

In this case, the server has either encountered an unexpected condition or is unable to fulfill the request. If the server encounters an issue, it should include an object with details about the error and whether or not it will persist (unless in the case of a HEAD request).

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 (Experimental)

507 Insufficient Storage (WebDAV)

508 Loop Detected (WebDAV)

509 Bandwidth Limit Exceeded (Apache)

510 Not Extended

511 Network Authentication Required

598 Network read timeout error

599 Network connect timeout error