Directory HTTP Status Codes (50) Search by code (e.g. 404, 429) or keyword (rate limit, cache, redirect) 100 Continue Initial part of a request has been received and the client should proceed with sending the request body.101 Switching Protocols Server agrees to switch application protocols as requested by the client Upgrade header.102 Processing Server has accepted the full request but has not yet completed long-running processing.103 Early Hints Lets the user agent preload linked assets while the server prepares the main response.200 OK The request succeeded and the response payload contains the requested resource or action result.201 Created The request succeeded and a new resource was created as a result.202 Accepted The request has been queued for asynchronous processing, which has not yet completed.203 Non-Authoritative Information Payload was modified by a transforming proxy from the origin server 200 OK response.204 No Content The server successfully processed the request and is not returning any response body.205 Reset Content Tells the client to reset the document view (such as clearing a form) after submission.206 Partial Content The server is delivering only part of the resource due to a Range header sent by the client.207 Multi-Status Conveys status for multiple independent operations in a single batch response.300 Multiple Choices The request has more than one possible response representation available.301 Moved Permanently The target resource has been assigned a new permanent URI.302 Found The target resource resides temporarily under a different URI.303 See Other Directs the client to fetch the resource at another URI using a GET request.304 Not Modified Resource has not been modified since the version specified by If-None-Match or If-Modified-Since.307 Temporary Redirect Temporary redirect that strictly preserves the HTTP method and request body.308 Permanent Redirect Permanent redirect that strictly preserves the original HTTP method and request body.400 Bad Request The server cannot or will not process the request due to malformed syntax or invalid parameters.401 Unauthorized The request lacks valid authentication credentials for the target resource.402 Payment Required Reserved for digital payment or subscription-gated APIs.403 Forbidden The server understood the request and authenticated the user, but refuses to authorize it.404 Not Found The server cannot find the requested resource or wishes to hide its existence from unauthorized clients.405 Method Not Allowed The request method is known by the server but is not supported by the target resource.406 Not Acceptable Server cannot produce a response matching the list of acceptable values in the request Accept headers.408 Request Timeout The server did not receive a complete request message within the time it was prepared to wait.409 Conflict The request could not be completed due to a conflict with the current state of the target resource.410 Gone Access to the target resource is no longer available and this condition is likely permanent.411 Length Required The server refuses to accept the request without a defined Content-Length header.412 Precondition Failed One or more conditions given in the request header fields evaluated to false when tested on the server.413 Content Too Large The request payload is larger than the server is willing or able to process.414 URI Too Long The request-target URI is longer than the server is willing to interpret.415 Unsupported Media Type The origin server refuses the payload because its Content-Type or Content-Encoding is unsupported.418 I'm a teapot The server refuses the attempt to brew coffee with a teapot (HTCPCP/1.0 April Fools spec).422 Unprocessable Content The syntax of the request body is valid, but semantic validation of the instructions failed.425 Too Early Indicates that the server is unwilling to risk processing a request that might be replayed in TLS 1.3 0-RTT.426 Upgrade Required The server refuses to perform the request using the current protocol but might after client upgrades.428 Precondition Required The origin server requires the request to be conditional to prevent the "lost update" problem.429 Too Many Requests The user has sent too many requests in a given amount of time ("rate limiting").431 Request Header Fields Too Large The server is unwilling to process the request because its header fields are too large.451 Unavailable For Legal Reasons The server is denying access to the resource as a consequence of a legal demand or geo-restriction.500 Internal Server Error The server encountered an unexpected condition or unhandled exception that prevented it from fulfilling the request.501 Not Implemented The server does not support the functionality required to fulfill the request.502 Bad Gateway The server, while acting as a gateway or proxy, received an invalid response from an inbound upstream server.503 Service Unavailable The server is currently unable to handle the request due to temporary overload or scheduled maintenance.504 Gateway Timeout The server, while acting as a gateway or proxy, did not receive a timely response from an upstream server.505 HTTP Version Not Supported The server does not support the major version of HTTP that was used in the request message.507 Insufficient Storage The server is unable to store the representation needed to complete the request.511 Network Authentication Required The client needs to authenticate to gain network access.
RFC Inspector 429 Too Many Requests Copy Status Line HTTP_TOO_MANY_REQUESTS The user has sent too many requests in a given amount of time ("rate limiting"). When to use in APIs API rate limiters, login brute-force protection, and token-bucket throttling. 4xx Class RFC 6585 §4 Specification No Cacheable Related HTTP Headers Retry-AfterX-RateLimit-LimitX-RateLimit-Remaining HTTP Response Wire Line HTTP/1.1 429 Too Many Requests