HTTP Status Code Reference
Look up any HTTP status code — what it means, its category, and when servers return it.
Covers the commonly-encountered codes from the IANA HTTP Status Code Registry — some rarely-used WebDAV/experimental codes aren't included.
4xx Client Error
404 Not Found
The server cannot find the requested resource.
All status codes
| Code | Message | Category |
|---|---|---|
| 100 | Continue | 1xx Informational |
| 101 | Switching Protocols | 1xx Informational |
| 200 | OK | 2xx Success |
| 201 | Created | 2xx Success |
| 202 | Accepted | 2xx Success |
| 204 | No Content | 2xx Success |
| 206 | Partial Content | 2xx Success |
| 301 | Moved Permanently | 3xx Redirection |
| 302 | Found | 3xx Redirection |
| 303 | See Other | 3xx Redirection |
| 304 | Not Modified | 3xx Redirection |
| 307 | Temporary Redirect | 3xx Redirection |
| 308 | Permanent Redirect | 3xx Redirection |
| 400 | Bad Request | 4xx Client Error |
| 401 | Unauthorized | 4xx Client Error |
| 402 | Payment Required | 4xx Client Error |
| 403 | Forbidden | 4xx Client Error |
| 404 | Not Found | 4xx Client Error |
| 405 | Method Not Allowed | 4xx Client Error |
| 406 | Not Acceptable | 4xx Client Error |
| 407 | Proxy Authentication Required | 4xx Client Error |
| 408 | Request Timeout | 4xx Client Error |
| 409 | Conflict | 4xx Client Error |
| 410 | Gone | 4xx Client Error |
| 411 | Length Required | 4xx Client Error |
| 412 | Precondition Failed | 4xx Client Error |
| 413 | Payload Too Large | 4xx Client Error |
| 414 | URI Too Long | 4xx Client Error |
| 415 | Unsupported Media Type | 4xx Client Error |
| 416 | Range Not Satisfiable | 4xx Client Error |
| 417 | Expectation Failed | 4xx Client Error |
| 418 | I'm a Teapot | 4xx Client Error |
| 422 | Unprocessable Entity | 4xx Client Error |
| 425 | Too Early | 4xx Client Error |
| 426 | Upgrade Required | 4xx Client Error |
| 429 | Too Many Requests | 4xx Client Error |
| 431 | Request Header Fields Too Large | 4xx Client Error |
| 451 | Unavailable For Legal Reasons | 4xx Client Error |
| 500 | Internal Server Error | 5xx Server Error |
| 501 | Not Implemented | 5xx Server Error |
| 502 | Bad Gateway | 5xx Server Error |
| 503 | Service Unavailable | 5xx Server Error |
| 504 | Gateway Timeout | 5xx Server Error |
| 505 | HTTP Version Not Supported | 5xx Server Error |
For informational and educational purposes only — not professional or technical advice, and not a substitute for consulting a qualified professional about your specific situation. TrueMeasureKit is not liable for decisions made based on these results. See our Terms of Service.
Why the first digit is all you strictly need to know
HTTP status codes are grouped into five classes by their first digit, and that top-level grouping is actually part of the HTTP spec — a client that doesn't recognize a specific code can still fall back to treating it according to its class (e.g. an unrecognized 4xx code should still be handled as some kind of client error). That's why generic error handling by class, with specific handling layered on top for well-known codes like 404 or 429, is a safe default when building against an API you don't fully control.
Frequently asked questions
How are status codes organized into categories?
1xx is informational, 2xx is success, 3xx is redirection, 4xx is a client error (the request was wrong), and 5xx is a server error (the server failed to fulfill a valid request) — the first digit tells you the category at a glance.