2025-09-15 RFC9110, Section 16.2.1 IETF Review 1xx: Informational - Request received, continuing process 2xx: Success - The action was successfully received, understood, and accepted 3xx: Redirection - Further action must be taken in order to complete the request 4xx: Client Error - The request contains bad syntax or cannot be fulfilled 5xx: Server Error - The server failed to fulfill an apparently valid request 100 Continue RFC9110, Section 15.2.1 101 Switching Protocols RFC9110, Section 15.2.2 102 Processing 103 Early Hints 104 Upload Resumption Supported (TEMPORARY - registered 2024-11-13, extension registered 2025-09-15, expires 2026-11-13) 105-199 Unassigned 200 OK RFC9110, Section 15.3.1 201 Created RFC9110, Section 15.3.2 202 Accepted RFC9110, Section 15.3.3 203 Non-Authoritative Information RFC9110, Section 15.3.4 204 No Content RFC9110, Section 15.3.5 205 Reset Content RFC9110, Section 15.3.6 206 Partial Content RFC9110, Section 15.3.7 207 Multi-Status 208 Already Reported 209-225 Unassigned 226 IM Used 227-299 Unassigned 300 Multiple Choices RFC9110, Section 15.4.1 301 Moved Permanently RFC9110, Section 15.4.2 302 Found RFC9110, Section 15.4.3 303 See Other RFC9110, Section 15.4.4 304 Not Modified RFC9110, Section 15.4.5 305 Use Proxy RFC9110, Section 15.4.6 306 (Unused) RFC9110, Section 15.4.7 307 Temporary Redirect RFC9110, Section 15.4.8 308 Permanent Redirect RFC9110, Section 15.4.9 309-399 Unassigned 400 Bad Request RFC9110, Section 15.5.1 401 Unauthorized RFC9110, Section 15.5.2 402 Payment Required RFC9110, Section 15.5.3 403 Forbidden RFC9110, Section 15.5.4 404 Not Found RFC9110, Section 15.5.5 405 Method Not Allowed RFC9110, Section 15.5.6 406 Not Acceptable RFC9110, Section 15.5.7 407 Proxy Authentication Required RFC9110, Section 15.5.8 408 Request Timeout RFC9110, Section 15.5.9 409 Conflict RFC9110, Section 15.5.10 410 Gone RFC9110, Section 15.5.11 411 Length Required RFC9110, Section 15.5.12 412 Precondition Failed RFC9110, Section 15.5.13 413 Content Too Large RFC9110, Section 15.5.14 414 URI Too Long RFC9110, Section 15.5.15 415 Unsupported Media Type RFC9110, Section 15.5.16 416 Range Not Satisfiable RFC9110, Section 15.5.17 417 Expectation Failed RFC9110, Section 15.5.18 418 (Unused) RFC9110, Section 15.5.19 419-420 Unassigned 421 Misdirected Request RFC9110, Section 15.5.20 422 Unprocessable Content RFC9110, Section 15.5.21 423 Locked 424 Failed Dependency 425 Too Early 426 Upgrade Required RFC9110, Section 15.5.22 427 Unassigned 428 Precondition Required 429 Too Many Requests 430 Unassigned 431 Request Header Fields Too Large 432-450 Unassigned 451 Unavailable For Legal Reasons 452-499 Unassigned 500 Internal Server Error RFC9110, Section 15.6.1 501 Not Implemented RFC9110, Section 15.6.2 502 Bad Gateway RFC9110, Section 15.6.3 503 Service Unavailable RFC9110, Section 15.6.4 504 Gateway Timeout RFC9110, Section 15.6.5 505 HTTP Version Not Supported RFC9110, Section 15.6.6 506 Variant Also Negotiates 507 Insufficient Storage 508 Loop Detected 509 Unassigned 510 Not Extended (OBSOLETED) Status change of HTTP experiments to Historic 511 Network Authentication Required 512-599 Unassigned