[ { "code": 100, "name": "Continue", "category": "1xx Informational", "description": "The server has received the request headers and the client should proceed to send the request body.", "specification": "RFC 9110", "commonCauses": [ "Client included an Expect: 100-continue header" ] }, { "code": 101, "name": "Switching Protocols", "category": "1xx Informational", "description": "The server is switching protocols as requested by the client via the Upgrade header.", "specification": "RFC 9110", "commonCauses": [ "WebSocket handshake", "HTTP/2 upgrade" ] }, { "code": 102, "name": "Processing", "category": "1xx Informational", "description": "WebDAV: The server has received and is processing the request, but no response is available yet.", "specification": "RFC 2518", "commonCauses": [ "Long-running WebDAV operation" ] }, { "code": 103, "name": "Early Hints", "category": "1xx Informational", "description": "Used to return some response headers before final HTTP message.", "specification": "RFC 8297", "commonCauses": [ "Server hinting Link headers for preload before final response" ] }, { "code": 200, "name": "OK", "category": "2xx Success", "description": "The request has succeeded. The information returned with the response is dependent on the method used in the request.", "specification": "RFC 9110", "commonCauses": [ "Successful GET, POST, PUT, or PATCH" ] }, { "code": 201, "name": "Created", "category": "2xx Success", "description": "The request has been fulfilled and resulted in a new resource being created.", "specification": "RFC 9110", "commonCauses": [ "POST that created a resource (return Location header)" ] }, { "code": 202, "name": "Accepted", "category": "2xx Success", "description": "The request has been accepted for processing, but the processing has not been completed.", "specification": "RFC 9110", "commonCauses": [ "Async job enqueued" ] }, { "code": 203, "name": "Non-Authoritative Information", "category": "2xx Success", "description": "The server is a transforming proxy that received a 200 OK from its origin, but is returning a modified version of the origin's response.", "specification": "RFC 9110", "commonCauses": [ "Response transformed by intermediate proxy" ] }, { "code": 204, "name": "No Content", "category": "2xx Success", "description": "The server successfully processed the request and is not returning any content.", "specification": "RFC 9110", "commonCauses": [ "DELETE succeeded", "PUT with no response body" ] }, { "code": 205, "name": "Reset Content", "category": "2xx Success", "description": "The server successfully processed the request, but is not returning any content. The user agent should reset the document view.", "specification": "RFC 9110", "commonCauses": [ "Form submission that should clear inputs" ] }, { "code": 206, "name": "Partial Content", "category": "2xx Success", "description": "The server is delivering only part of the resource due to a range header sent by the client.", "specification": "RFC 9110", "commonCauses": [ "Range request", "Resumable download" ] }, { "code": 207, "name": "Multi-Status", "category": "2xx Success", "description": "WebDAV: The message body contains an XML message with multiple status codes for separate operations.", "specification": "RFC 4918", "commonCauses": [ "WebDAV PROPFIND or batch operation" ] }, { "code": 208, "name": "Already Reported", "category": "2xx Success", "description": "WebDAV: The members of a DAV binding have already been enumerated and are not being included again.", "specification": "RFC 5842", "commonCauses": [ "WebDAV bind extension" ] }, { "code": 226, "name": "IM Used", "category": "2xx Success", "description": "The server has fulfilled a request and the response is a representation of the result of one or more instance-manipulations.", "specification": "RFC 3229", "commonCauses": [ "Delta encoding response" ] }, { "code": 300, "name": "Multiple Choices", "category": "3xx Redirection", "description": "Indicates multiple options for the resource from which the client may choose.", "specification": "RFC 9110", "commonCauses": [ "Content negotiation with multiple representations" ] }, { "code": 301, "name": "Moved Permanently", "category": "3xx Redirection", "description": "This and all future requests should be directed to the given URI.", "specification": "RFC 9110", "commonCauses": [ "Permanent URL change", "Domain migration" ] }, { "code": 302, "name": "Found", "category": "3xx Redirection", "description": "Tells the client to look at (browse to) another URL. The original URL still applies for future requests.", "specification": "RFC 9110", "commonCauses": [ "Temporary redirect (legacy use; prefer 307)" ] }, { "code": 303, "name": "See Other", "category": "3xx Redirection", "description": "The response to the request can be found under another URI using the GET method.", "specification": "RFC 9110", "commonCauses": [ "Post/Redirect/Get pattern" ] }, { "code": 304, "name": "Not Modified", "category": "3xx Redirection", "description": "Indicates that the resource has not been modified since the version specified by the request headers.", "specification": "RFC 9110", "commonCauses": [ "Conditional GET with If-None-Match or If-Modified-Since" ] }, { "code": 305, "name": "Use Proxy", "category": "3xx Redirection", "description": "Deprecated. The requested resource is available only through a proxy.", "specification": "RFC 7231", "commonCauses": [ "Legacy use; deprecated for security reasons" ] }, { "code": 307, "name": "Temporary Redirect", "category": "3xx Redirection", "description": "In this case, the request should be repeated with another URI; however, future requests should still use the original URI. The method must not change.", "specification": "RFC 9110", "commonCauses": [ "Temporary redirect preserving HTTP method" ] }, { "code": 308, "name": "Permanent Redirect", "category": "3xx Redirection", "description": "The request and all future requests should be repeated using another URI. The method must not change.", "specification": "RFC 7538", "commonCauses": [ "Permanent redirect preserving HTTP method" ] }, { "code": 400, "name": "Bad Request", "category": "4xx Client Error", "description": "The server cannot or will not process the request due to an apparent client error.", "specification": "RFC 9110", "commonCauses": [ "Malformed JSON", "Missing required parameters", "Invalid syntax" ] }, { "code": 401, "name": "Unauthorized", "category": "4xx Client Error", "description": "Authentication is required and has failed or has not yet been provided.", "specification": "RFC 9110", "commonCauses": [ "Missing or invalid Authorization header", "Expired token" ] }, { "code": 402, "name": "Payment Required", "category": "4xx Client Error", "description": "Reserved for future use. Sometimes used by APIs to indicate exceeding a free-tier quota.", "specification": "RFC 9110", "commonCauses": [ "Quota exceeded", "Subscription required" ] }, { "code": 403, "name": "Forbidden", "category": "4xx Client Error", "description": "The request was valid, but the server is refusing action. The user might not have the necessary permissions.", "specification": "RFC 9110", "commonCauses": [ "Insufficient permissions", "IP block", "CORS rejection at origin" ] }, { "code": 404, "name": "Not Found", "category": "4xx Client Error", "description": "The requested resource could not be found but may be available in the future.", "specification": "RFC 9110", "commonCauses": [ "Wrong URL", "Resource deleted", "Typo in path" ] }, { "code": 405, "name": "Method Not Allowed", "category": "4xx Client Error", "description": "A request method is not supported for the requested resource.", "specification": "RFC 9110", "commonCauses": [ "Sending POST to a GET-only endpoint" ] }, { "code": 406, "name": "Not Acceptable", "category": "4xx Client Error", "description": "The requested resource is capable of generating only content not acceptable according to the Accept headers.", "specification": "RFC 9110", "commonCauses": [ "Accept header mismatch" ] }, { "code": 407, "name": "Proxy Authentication Required", "category": "4xx Client Error", "description": "The client must first authenticate itself with the proxy.", "specification": "RFC 9110", "commonCauses": [ "Forward proxy requires credentials" ] }, { "code": 408, "name": "Request Timeout", "category": "4xx Client Error", "description": "The server timed out waiting for the request.", "specification": "RFC 9110", "commonCauses": [ "Slow network", "Idle keep-alive timeout" ] }, { "code": 409, "name": "Conflict", "category": "4xx Client Error", "description": "Indicates that the request could not be processed because of conflict in the current state of the resource.", "specification": "RFC 9110", "commonCauses": [ "Concurrent edit", "Version mismatch", "Duplicate key" ] }, { "code": 410, "name": "Gone", "category": "4xx Client Error", "description": "Indicates that the resource requested is no longer available and will not be available again.", "specification": "RFC 9110", "commonCauses": [ "Deprecated endpoint", "Permanently removed resource" ] }, { "code": 411, "name": "Length Required", "category": "4xx Client Error", "description": "The request did not specify the length of its content, which is required by the requested resource.", "specification": "RFC 9110", "commonCauses": [ "Missing Content-Length on a method that requires it" ] }, { "code": 412, "name": "Precondition Failed", "category": "4xx Client Error", "description": "The server does not meet one of the preconditions specified in the request headers.", "specification": "RFC 9110", "commonCauses": [ "If-Match or If-Unmodified-Since failed" ] }, { "code": 413, "name": "Content Too Large", "category": "4xx Client Error", "description": "The request is larger than the server is willing or able to process.", "specification": "RFC 9110", "commonCauses": [ "File upload too large", "Body exceeds limit" ] }, { "code": 414, "name": "URI Too Long", "category": "4xx Client Error", "description": "The URI provided was too long for the server to process.", "specification": "RFC 9110", "commonCauses": [ "Excessive query string", "Long path" ] }, { "code": 415, "name": "Unsupported Media Type", "category": "4xx Client Error", "description": "The request entity has a media type which the server or resource does not support.", "specification": "RFC 9110", "commonCauses": [ "Wrong Content-Type", "Sent XML to JSON-only endpoint" ] }, { "code": 416, "name": "Range Not Satisfiable", "category": "4xx Client Error", "description": "The client has asked for a portion of the file, but the server cannot supply that portion.", "specification": "RFC 9110", "commonCauses": [ "Range outside resource bounds" ] }, { "code": 417, "name": "Expectation Failed", "category": "4xx Client Error", "description": "The server cannot meet the requirements of the Expect request-header field.", "specification": "RFC 9110", "commonCauses": [ "Server does not support Expect: 100-continue" ] }, { "code": 418, "name": "I'm a teapot", "category": "4xx Client Error", "description": "Returned by teapots requested to brew coffee. An April Fools' joke standardised in RFC 2324.", "specification": "RFC 2324", "commonCauses": [ "Used as an Easter egg or generic refusal indicator" ] }, { "code": 421, "name": "Misdirected Request", "category": "4xx Client Error", "description": "The request was directed at a server that is not able to produce a response.", "specification": "RFC 9110", "commonCauses": [ "HTTP/2 connection coalescing edge case" ] }, { "code": 422, "name": "Unprocessable Content", "category": "4xx Client Error", "description": "The request was well-formed but was unable to be followed due to semantic errors.", "specification": "RFC 9110", "commonCauses": [ "Validation error in payload" ] }, { "code": 423, "name": "Locked", "category": "4xx Client Error", "description": "WebDAV: The resource that is being accessed is locked.", "specification": "RFC 4918", "commonCauses": [ "WebDAV resource lock held by another client" ] }, { "code": 424, "name": "Failed Dependency", "category": "4xx Client Error", "description": "WebDAV: The request failed because it depended on another request and that request failed.", "specification": "RFC 4918", "commonCauses": [ "WebDAV chained operation failure" ] }, { "code": 425, "name": "Too Early", "category": "4xx Client Error", "description": "Indicates that the server is unwilling to risk processing a request that might be replayed.", "specification": "RFC 8470", "commonCauses": [ "TLS 1.3 0-RTT protection" ] }, { "code": 426, "name": "Upgrade Required", "category": "4xx Client Error", "description": "The client should switch to a different protocol such as TLS/1.3.", "specification": "RFC 9110", "commonCauses": [ "Server requires HTTPS or HTTP/2" ] }, { "code": 428, "name": "Precondition Required", "category": "4xx Client Error", "description": "The origin server requires the request to be conditional.", "specification": "RFC 6585", "commonCauses": [ "API requires If-Match for concurrency safety" ] }, { "code": 429, "name": "Too Many Requests", "category": "4xx Client Error", "description": "The user has sent too many requests in a given amount of time.", "specification": "RFC 6585", "commonCauses": [ "Rate limit exceeded" ] }, { "code": 431, "name": "Request Header Fields Too Large", "category": "4xx Client Error", "description": "The server is unwilling to process the request because either an individual header field, or all the header fields collectively, are too large.", "specification": "RFC 6585", "commonCauses": [ "Oversized cookie", "Excessive headers" ] }, { "code": 451, "name": "Unavailable For Legal Reasons", "category": "4xx Client Error", "description": "A server operator has received a legal demand to deny access to a resource.", "specification": "RFC 7725", "commonCauses": [ "Geo-block due to court order", "DMCA takedown" ] }, { "code": 500, "name": "Internal Server Error", "category": "5xx Server Error", "description": "A generic error message, given when an unexpected condition was encountered.", "specification": "RFC 9110", "commonCauses": [ "Unhandled exception", "Bug", "Database error" ] }, { "code": 501, "name": "Not Implemented", "category": "5xx Server Error", "description": "The server either does not recognize the request method, or it lacks the ability to fulfil the request.", "specification": "RFC 9110", "commonCauses": [ "HTTP method not supported" ] }, { "code": 502, "name": "Bad Gateway", "category": "5xx Server Error", "description": "The server was acting as a gateway or proxy and received an invalid response from the upstream server.", "specification": "RFC 9110", "commonCauses": [ "Upstream service down", "Reverse proxy received invalid response" ] }, { "code": 503, "name": "Service Unavailable", "category": "5xx Server Error", "description": "The server is currently unavailable (because it is overloaded or down for maintenance).", "specification": "RFC 9110", "commonCauses": [ "Maintenance window", "Overload", "Circuit breaker open" ] }, { "code": 504, "name": "Gateway Timeout", "category": "5xx Server Error", "description": "The server was acting as a gateway or proxy and did not receive a timely response from the upstream server.", "specification": "RFC 9110", "commonCauses": [ "Upstream server slow", "Connection timed out" ] }, { "code": 505, "name": "HTTP Version Not Supported", "category": "5xx Server Error", "description": "The server does not support the HTTP protocol version used in the request.", "specification": "RFC 9110", "commonCauses": [ "Unsupported HTTP version requested" ] }, { "code": 506, "name": "Variant Also Negotiates", "category": "5xx Server Error", "description": "Transparent content negotiation for the request results in a circular reference.", "specification": "RFC 2295", "commonCauses": [ "Misconfigured content negotiation" ] }, { "code": 507, "name": "Insufficient Storage", "category": "5xx Server Error", "description": "WebDAV: The server is unable to store the representation needed to complete the request.", "specification": "RFC 4918", "commonCauses": [ "Disk full", "Quota exceeded server-side" ] }, { "code": 508, "name": "Loop Detected", "category": "5xx Server Error", "description": "WebDAV: The server detected an infinite loop while processing the request.", "specification": "RFC 5842", "commonCauses": [ "Cyclical WebDAV bindings" ] }, { "code": 510, "name": "Not Extended", "category": "5xx Server Error", "description": "Further extensions to the request are required for the server to fulfil it.", "specification": "RFC 2774", "commonCauses": [ "Required extension declaration missing" ] }, { "code": 511, "name": "Network Authentication Required", "category": "5xx Server Error", "description": "The client needs to authenticate to gain network access.", "specification": "RFC 6585", "commonCauses": [ "Captive portal", "Public Wi-Fi login required" ] } ]