Error Code List

1. 1xx Informational Error Code List
2. 2xx Success Error Code List
3. 3xx Redirection Error Code List
4. 4xx Client Error Code List
5. 5xx Server Error Code List
6. Unofficial Error Code List

1xx Informational Error Code List

This class of status code means a temporary response, consisting notably of the Status-Line and optional headers, and is eliminated by an empty line.

Since HTTP/1.0 did not specify any 1xx status codes, servers must not[note 1] transfer a 1xx response to an HTTP/1.0 client but under experimental circumstances.

HTTP Error Code 100 Continue

HTTP Error Code 101 Switching Protocols

HTTP Error Code 102 Processing

2xx Success Error Code List

This class of status codes means the action asked by the client was accepted, understood and processed successfully.

200 – OK

201 – Created

202 – Accepted

203 – Non-Authoritative Information (since HTTP/1.1)

204 – No Content

205 – Reset Content

206 – Partial Content (RFC 7233)

207 – Multi-Status (WebDAV; RFC 4918)

208 – Already Reported (WebDAV; RFC 5842)

226 – IM Used (RFC 3229)

3xx Redirection Error Code List

This class of status code means the client must take extra action to complete the request. Several of these status codes used in URL redirection. A user agent may carry out the further action with no user interaction only if the system utilised in the second request is GET or HEAD. A user may automatically redirect a request. A user agent should detect and interrupt to prevent cyclical redirects.

300 – Multiple Choices

301 – Moved Permanently

302 – Found

303 – Check Other (since HTTP/1.1)

304 – Not Modified (RFC 7232)

305 – Use Proxy (since HTTP/1.1)

306 – Switch Proxy

307 – Temporary Redirect (since HTTP/1.1)

308 – Permanent Redirect (RFC 7538)

4xx Client Error Code List

This class of status code is reserved for conditions in which the client seems to have erred.

400 – Bad Request

401 – Unauthorised (RFC 7235)

402 – Payment Required

403 – Forbidden

404 – Not Found

405 – Method Not Allowed

406 – Not Acceptable

407 – Proxy Authentication Required (RFC 7235)

408 – Request Timeout

409 – Conflict

410 – Gone

411 – Length Required

412 – Precondition Failed (RFC 7232)

413 – Payload Too Large (RFC 7231)

414 – URI Too Long (RFC 7231)

415 – Unsupported Media Type

416 – Range Not Satisfiable (RFC 7233)

417 – Expectation Failed

418 – I’m a teapot (RFC 2324)

421 – Misdirected Request (RFC 7540)

422 – Unprocessable Entity (WebDAV; RFC 4918)

423 – Locked (WebDAV; RFC 4918)

424 – Failed Dependency (WebDAV; RFC 4918)

426 – Upgrade Required

428 – Precondition Required (RFC 6585)

429 – Too Many Requests (RFC 6585)

431 – Request Header Fields Too Large (RFC 6585)

451 – Unavailable For Legal Reasons

5xx Server Error Code List

The server failed to fulfil a possibly valid request. These response codes apply to any request method.

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 (RFC 2295)

507 – Insufficient Storage (WebDAV; RFC 4918)

508 – Loop Detected (WebDAV; RFC 5842)

510 – Not Extended (RFC 2774)

511 – Network Authentication Required (RFC 6585)

Unofficial Error Code List

These codes are not defined in any RFC but are used by 3rd-party services to provide RESTful error responses.

103 – Checkpoint

420 – Method Failure (Spring Framework)

420 – Enhance Your Calm (Twitter)

450 – Blocked by Windows Parental Controls (Microsoft)

498 – Invalid Token (Esri)

499 – Token Required (Esri)

499 – Request forbidden by antivirus

509 – Bandwidth Limit Exceeded (Apache Web Server/cPanel)

530 – Site is frozen

Internet Information Services Error Code List

IIS expands 4xx error space to signal errors.

449 – Retry With

451 – Redirect

444 – No Response

Nginx Error Code List

The nginx web server software extends the 4xx error space to indicate issues with the client’s request. These codes used for only logging purposes. No actual response is sent with these codes.

495 – SSL Certificate Error

496 – SSL Certificate Required

497 – HTTP Request Sent to HTTPS Port

499 – Client Closed Request

CloudFlare Error Code List

CloudFlare’s reverse proxy service expands the 5xx series of errors space to signal issues with the origin server.

520 – Unknown Error

521 – Web Server Is Down

522 – Connection Timed Out

523 – Origin Is Unreachable

524 – A Timeout Occurred

525 – SSL Handshake Failed

526 – Invalid SSL Certificate