HTTP Status Code Reference
Continue
The server has received the request headers, and the client should continue sending the request body.
Switching Protocols
The server is switching protocols as requested by the client (e.g., upgrading to WebSocket).
Processing
The server has received and is processing the request, but no response is available yet (WebDAV).
Early Hints
Returning partial headers before the final response to allow the browser to preload resources.
OK
Request succeeded, and the response contains the requested data.
Created
Request succeeded, and the server created a new resource.
Accepted
Request accepted, but processing not yet completed (asynchronous processing).
Non-Authoritative Information
The returned meta-information is from a third-party copy, not the origin server.
No Content
Request succeeded, but there is no response body content.
Reset Content
Request succeeded, and the client should reset the current page view (e.g., clear a form).
Partial Content
The server successfully returned partial content (for resumable downloads or segmented downloads).
Multi-Status
Multi-status response, with the body containing the status of multiple resources (WebDAV).
Already Reported
Binding members have already been enumerated and will not be listed again (WebDAV).
IM Used
The server has completed the instance manipulation of the resource and returned the result.
Multiple Choices
The requested resource has multiple possible representations, and the client must choose one.
Moved Permanently
The resource has permanently moved to a new address, and subsequent requests should use the new URL.
Found
The resource is temporarily located at another address, and subsequent requests should still use the original URL.
See Other
The client should use the GET method to access another address to obtain the result (common after form submission).
Not Modified
The resource has not been modified and can be used directly from the local cache.
Temporary Redirect
The resource is temporarily redirected, and the original request method must be preserved.
Permanent Redirect
The resource is permanently redirected, and the original request method must be preserved.
Bad Request
The request has a syntax error or invalid parameters, and the server cannot understand it.
Unauthorized
Authentication is required, please provide valid login credentials.
Payment Required
Reserved for future payment scenarios, rarely used currently.
Forbidden
The server understood the request but refused to execute it due to insufficient permissions.
Not Found
The requested resource could not be found; the address may be incorrect or has been deleted.
Method Not Allowed
The request method is not allowed for this resource (e.g., using POST on a read-only interface).
Not Acceptable
The server cannot return content that matches the client's Accept requirements.
Proxy Authentication Required
Authentication through a proxy server is required first.
Request Timeout
Client request timeout; server terminated the connection.
Conflict
Request conflicts with the current state of the resource (e.g., concurrent edit).
Gone
Resource permanently deleted and will not be restored.
Length Required
Request missing required Content-Length header.
Precondition Failed
Precondition in request header not met.
Payload Too Large
Request body too large, exceeding server limit.
URI Too Long
Requested URI too long for server to process.
Unsupported Media Type
Media type of request body not supported by server.
Range Not Satisfiable
Requested range cannot be satisfied (e.g., exceeds file size).
Expectation Failed
Expectation in request header Expect field cannot be met.
I'm a teapot
I'm a teapot—I can't brew coffee—April Fool's joke status code.
Misdirected Request
Request directed to a server unable to produce a response.
Unprocessable Entity
Request well-formed but semantically erroneous and cannot be processed (common with validation failure).
Locked
Target resource locked and temporarily unavailable (WebDAV).
Failed Dependency
Request failed due to failure of a dependent previous request (WebDAV).
Too Early
Server unwilling to process request that might be replayed.
Upgrade Required
Client needs to upgrade to another protocol to continue.
Precondition Required
Request requires preconditions to avoid conflicting updates.
Too Many Requests
Too many requests; rate limit triggered. Please retry later.
Request Header Fields Too Large
Request header fields too large; server refusing to process.
Unavailable For Legal Reasons
Resource inaccessible due to legal reasons.
Internal Server Error
Unexpected internal server error.
Not Implemented
Server does not support functionality required by the request.
Bad Gateway
Invalid response received from upstream server as gateway or proxy.
Service Unavailable
Server temporarily unavailable (overloaded or under maintenance). Please retry later.
Gateway Timeout
Gateway or proxy timeout waiting for upstream server response.
HTTP Version Not Supported
Server does not support HTTP protocol version used in request.
Variant Also Negotiates
Content negotiation configuration error causing circular reference.
Insufficient Storage
Insufficient server storage space to complete request (WebDAV).
Loop Detected
Infinite loop detected during request processing (WebDAV).
Not Extended
The request requires further extension to be satisfied by the server.
Network Authentication Required
Network authentication is required before access (e.g., connecting to public Wi-Fi).
Frequently Asked Questions
They are divided into five categories by the first digit: 1xx Information (request received, continue processing), 2xx Success, 3xx Redirection, 4xx Client Error (problem with the request), 5xx Server Error (server failed to process the request).