HTTP Status Codes
Every code, in plain English.
1xx · Informational
| 100 | Continue | Headers accepted; send the request body. |
| 101 | Switching Protocols | Protocol upgrade accepted (e.g. to WebSocket). |
| 102 | Processing | WebDAV: request received, still working on it. |
| 103 | Early Hints | Preload headers sent before the final response. |
2xx · Success
| 200 | OK | Request succeeded; body carries the result. |
| 201 | Created | A new resource was created (typical POST answer). |
| 202 | Accepted | Queued for later processing; no result yet. |
| 203 | Non-Authoritative Information | A proxy modified the response headers. |
| 204 | No Content | Success with an empty body — common for DELETE. |
| 205 | Reset Content | Success; the client should reset its form/view. |
| 206 | Partial Content | Answer to a Range request (resumable downloads). |
| 207 | Multi-Status | WebDAV: per-resource statuses in one body. |
| 208 | Already Reported | WebDAV: members already listed, not repeated. |
| 226 | IM Used | Delta encoding applied to the response. |
3xx · Redirection
| 300 | Multiple Choices | Several representations; client must pick. |
| 301 | Moved Permanently | New canonical URL; update bookmarks and SEO. |
| 302 | Found | Temporary redirect (historically misused for 303). |
| 303 | See Other | Follow with GET to a different URL — right after POST. |
| 304 | Not Modified | Cached copy is still fresh; no body sent. |
| 307 | Temporary Redirect | Redirect keeping the method and body. |
| 308 | Permanent Redirect | 301 that also keeps the method and body. |
4xx · Client errors
| 400 | Bad Request | Malformed syntax or invalid parameters. |
| 401 | Unauthorized | Missing or bad authentication credentials. |
| 402 | Payment Required | Reserved; used by some APIs for billing blocks. |
| 403 | Forbidden | Authenticated or not, you may not do this. |
| 404 | Not Found | No resource at this URL (or none you may see). |
| 405 | Method Not Allowed | Resource exists, but not for this verb. |
| 406 | Not Acceptable | No representation matching the Accept headers. |
| 407 | Proxy Authentication Required | Authenticate with the proxy first. |
| 408 | Request Timeout | Client took too long to send the request. |
| 409 | Conflict | State conflict — e.g. edit war or duplicate create. |
| 410 | Gone | Deleted on purpose, permanently. |
| 411 | Length Required | Content-Length header is required. |
| 412 | Precondition Failed | An If-* header condition was not met. |
| 413 | Content Too Large | Request body bigger than the server allows. |
| 414 | URI Too Long | The request target exceeds server limits. |
| 415 | Unsupported Media Type | Body format the server cannot handle. |
| 416 | Range Not Satisfiable | Requested range falls outside the resource. |
| 417 | Expectation Failed | The Expect header cannot be satisfied. |
| 418 | I'm a teapot | RFC 2324 Easter egg — refuses to brew coffee. |
| 421 | Misdirected Request | Sent to a server not authoritative for it. |
| 422 | Unprocessable Content | Well-formed but semantically invalid. |
| 423 | Locked | WebDAV: the resource is locked. |
| 424 | Failed Dependency | WebDAV: a dependent action failed. |
| 425 | Too Early | Server refuses to replay a risky early request. |
| 426 | Upgrade Required | Client must switch protocols (e.g. TLS). |
| 428 | Precondition Required | Server requires If-Match-style headers. |
| 429 | Too Many Requests | Rate limited — check Retry-After. |
| 431 | Request Header Fields Too Large | Headers exceed server limits. |
| 451 | Unavailable For Legal Reasons | Blocked for legal demands (Fahrenheit 451). |
5xx · Server errors
| 500 | Internal Server Error | Generic server-side failure. |
| 501 | Not Implemented | The server does not support this functionality. |
| 502 | Bad Gateway | Upstream server sent an invalid response. |
| 503 | Service Unavailable | Overloaded or down for maintenance. |
| 504 | Gateway Timeout | Upstream server took too long. |
| 505 | HTTP Version Not Supported | The request line used an unknown version. |
| 506 | Variant Also Negotiates | Content negotiation misconfiguration. |
| 507 | Insufficient Storage | WebDAV: no space left to complete the action. |
| 508 | Loop Detected | WebDAV: infinite loop while processing. |
| 510 | Not Extended | Further extensions are required. |
| 511 | Network Authentication Required | Captive portal wants a login. |
About this tool
A searchable reference of HTTP status codes — 1xx through 5xx — with one-line explanations of what each means and when you would see it.
It runs completely in your browser — no input is sent anywhere, and this page loads no ads or third-party scripts, so it is safe to use with data you would not paste into a hosted service.