HTTP Status Code Reference
Quick reference for HTTP status codes with descriptions and usage examples
100Continue
The server has received the request headers and the client should proceed to send the request body.
Common Usage:
Used with large requests that need approval before sending the body.
101Switching Protocols
The requester has asked the server to switch protocols and the server has agreed to do so.
Common Usage:
Common in WebSocket upgrades.
102Processing
The server has received and is processing the request, but no response is available yet.
Common Usage:
Used in WebDAV to prevent client timeout.
200OK
The request has succeeded.
Common Usage:
Standard response for successful HTTP requests.
201Created
The request has been fulfilled and resulted in a new resource being created.
Common Usage:
Typically returned after POST requests that create new resources.
202Accepted
The request has been accepted for processing, but the processing has not been completed.
Common Usage:
Used for asynchronous processing.
204No Content
The server successfully processed the request and is not returning any content.
Common Usage:
Common response to DELETE requests or PUT requests without response data.
301Moved Permanently
This and all future requests should be directed to the given URI.
Common Usage:
Used for permanent URL changes. SEO-friendly redirect.
302Found
The resource is temporarily located at a different URI.
Common Usage:
Temporary redirect. The original URL should be used for future requests.
304Not Modified
The resource has not been modified since the last request.
Common Usage:
Used with conditional requests for caching.
400Bad Request
The server cannot or will not process the request due to a client error.
Common Usage:
Invalid request syntax or malformed request.
401Unauthorized
Authentication is required and has failed or has not been provided.
Common Usage:
User must authenticate to access the resource.
403Forbidden
The server understood the request but refuses to authorize it.
Common Usage:
User is authenticated but lacks permission for the resource.
404Not Found
The requested resource could not be found.
Common Usage:
The most common error. Resource doesn't exist.
405Method Not Allowed
The request method is not supported for the requested resource.
Common Usage:
Wrong HTTP method (e.g., POST to a read-only endpoint).
409Conflict
The request could not be processed because of conflict in the current state of the resource.
Common Usage:
Resource conflicts, such as duplicate entries.
422Unprocessable Entity
The request was well-formed but was unable to be followed due to semantic errors.
Common Usage:
Validation errors in request data.
429Too Many Requests
The user has sent too many requests in a given amount of time.
Common Usage:
Rate limiting is in effect.
500Internal Server Error
A generic error message when an unexpected condition was encountered.
Common Usage:
General server error when no specific error is appropriate.
501Not Implemented
The server either does not recognize the request method or lacks the ability to fulfill the request.
Common Usage:
Server doesn't support the functionality required.
502Bad Gateway
The server was acting as a gateway or proxy and received an invalid response from the upstream server.
Common Usage:
Common in load balancers and reverse proxies.
503Service Unavailable
The server is currently unavailable due to temporary overload or maintenance.
Common Usage:
Server is temporarily down or overloaded.
504Gateway Timeout
The server was acting as a gateway or proxy and did not receive a timely response from the upstream server.
Common Usage:
Timeout in proxy or gateway configurations.
HTTP Status Code Categories:
- 1xx (Informational): Request received, continuing process
- 2xx (Success): Request successfully received, understood, and accepted
- 3xx (Redirection): Further action needs to be taken to complete the request
- 4xx (Client Error): Request contains bad syntax or cannot be fulfilled
- 5xx (Server Error): Server failed to fulfill an apparently valid request