HTTP Status Code Reference
Comprehensive reference for HTTP status codes with descriptions and use cases
1xx Informational
Continue
The server has received the request headers and the client should proceed to send the request body.
Common Use Cases:
- •Used when uploading large files
- •When client expects a 100-continue response
Switching Protocols
The server is switching protocols as requested by the client.
Common Use Cases:
- •Upgrading from HTTP to WebSocket
- •Protocol negotiation
Processing
The server has received and is processing the request, but no response is available yet.
Common Use Cases:
- •Long-running WebDAV requests
- •Preventing client timeout
Early Hints
Used to return some response headers before final HTTP message.
Common Use Cases:
- •Preloading resources
- •Performance optimization
2xx Success
OK
The request succeeded. The meaning of success depends on the HTTP method.
Common Use Cases:
- •Successful GET request
- •Successful POST/PUT/PATCH request
- •Most common success response
Created
The request succeeded and a new resource was created as a result.
Common Use Cases:
- •POST request that creates a new resource
- •New user registration
- •Creating a new record
Accepted
The request has been received but not yet acted upon.
Common Use Cases:
- •Asynchronous processing
- •Batch operations
- •Queue-based systems
Non-Authoritative Information
The request was successful but the enclosed payload has been modified by a transforming proxy.
Common Use Cases:
- •Proxy modifications
- •Cached responses with modifications
No Content
The server successfully processed the request but is not returning any content.
Common Use Cases:
- •Successful DELETE request
- •Form submission without redirect
- •Auto-save operations
Reset Content
The server successfully processed the request and is asking the client to reset the document view.
Common Use Cases:
- •Form reset after submission
- •Clear input fields
Partial Content
The server is delivering only part of the resource due to a range header sent by the client.
Common Use Cases:
- •Video/audio streaming
- •Resume interrupted downloads
- •Loading large files in chunks
3xx Redirection
Multiple Choices
The request has more than one possible response.
Common Use Cases:
- •Multiple format options
- •Content negotiation
Moved Permanently
The URL of the requested resource has been changed permanently.
Common Use Cases:
- •SEO-friendly redirects
- •Domain changes
- •URL structure changes
Found
The URI of requested resource has been changed temporarily.
Common Use Cases:
- •Temporary redirects
- •A/B testing
- •Maintenance mode
See Other
The server sent this response to direct the client to get the requested resource at another URI with a GET request.
Common Use Cases:
- •POST/PUT/DELETE redirect pattern
- •Preventing form resubmission
Not Modified
The resource has not been modified since the version specified by the request headers.
Common Use Cases:
- •Browser caching
- •Conditional GET requests
- •Bandwidth optimization
Temporary Redirect
The server sends this response to direct the client to get the requested resource at another URI with same method.
Common Use Cases:
- •Temporary redirects preserving method
- •Server maintenance
Permanent Redirect
The resource is now permanently located at another URI, and the request method should not be changed.
Common Use Cases:
- •Permanent redirects preserving POST method
- •API versioning
4xx Client Error
Bad Request
The server cannot process the request due to client error (e.g., malformed syntax).
Common Use Cases:
- •Invalid JSON payload
- •Missing required parameters
- •Malformed request syntax
Unauthorized
The client must authenticate itself to get the requested response.
Common Use Cases:
- •Missing authentication token
- •Invalid credentials
- •Expired session
Payment Required
Reserved for future use. Originally intended for digital payment systems.
Common Use Cases:
- •Paywall content
- •Subscription required
- •Payment processing
Forbidden
The client does not have access rights to the content.
Common Use Cases:
- •Insufficient permissions
- •IP blocking
- •Authentication succeeded but authorization failed
Not Found
The server cannot find the requested resource.
Common Use Cases:
- •Page not found
- •Resource deleted
- •Invalid URL
Method Not Allowed
The request method is not supported for the requested resource.
Common Use Cases:
- •Using POST on GET-only endpoint
- •DELETE not allowed
- •Method restrictions
Not Acceptable
The server cannot produce a response matching the list of acceptable values in the request headers.
Common Use Cases:
- •Content negotiation failure
- •Unsupported Accept header
Proxy Authentication Required
Authentication must be done by a proxy.
Common Use Cases:
- •Corporate proxy authentication
- •Network access control
Request Timeout
The server timed out waiting for the request.
Common Use Cases:
- •Slow network connection
- •Client taking too long to send request
Conflict
The request conflicts with the current state of the server.
Common Use Cases:
- •Concurrent updates
- •Version conflicts
- •Duplicate resource creation
Gone
The requested resource is no longer available and will not be available again.
Common Use Cases:
- •Permanently deleted resource
- •Expired content
- •API deprecation
Length Required
The server requires the Content-Length header.
Common Use Cases:
- •Missing Content-Length in POST/PUT
- •Upload requirements
Precondition Failed
The server does not meet one of the preconditions in the request headers.
Common Use Cases:
- •Conditional requests
- •If-Match header failures
- •Optimistic locking
Payload Too Large
Request entity is larger than limits defined by server.
Common Use Cases:
- •File upload size limit
- •Request body too large
- •JSON payload size limit
URI Too Long
The URI requested by the client is longer than the server is willing to interpret.
Common Use Cases:
- •Excessive query parameters
- •Long URLs
- •GET request with too much data
Unsupported Media Type
The media format of the requested data is not supported by the server.
Common Use Cases:
- •Wrong Content-Type header
- •Unsupported file format
- •API expects JSON but receives XML
Range Not Satisfiable
The range specified by the Range header cannot be fulfilled.
Common Use Cases:
- •Invalid byte range request
- •Streaming range errors
Expectation Failed
The expectation indicated by the Expect header cannot be met.
Common Use Cases:
- •100-continue expectation not met
I'm a teapot
The server refuses to brew coffee because it is a teapot (April Fools' joke in RFC 2324).
Common Use Cases:
- •Easter egg
- •Joke status code
Misdirected Request
The request was directed at a server that is not able to produce a response.
Common Use Cases:
- •HTTP/2 server mismatch
Unprocessable Entity
The request was well-formed but contains semantic errors.
Common Use Cases:
- •Validation errors
- •Business logic errors
- •Invalid field values
Locked
The resource being accessed is locked.
Common Use Cases:
- •WebDAV locked resources
- •Resource being edited by another user
Failed Dependency
The request failed due to failure of a previous request.
Common Use Cases:
- •WebDAV dependent request failures
Too Early
The server is unwilling to risk processing a request that might be replayed.
Common Use Cases:
- •Preventing replay attacks
Upgrade Required
The server refuses to perform the request using the current protocol.
Common Use Cases:
- •Force HTTPS upgrade
- •Protocol version upgrade
Precondition Required
The server requires the request to be conditional.
Common Use Cases:
- •Lost update problem prevention
- •Requiring If-Match header
Too Many Requests
The user has sent too many requests in a given amount of time.
Common Use Cases:
- •Rate limiting
- •API throttling
- •DDoS protection
Request Header Fields Too Large
The server refuses to process the request because header fields are too large.
Common Use Cases:
- •Cookie size too large
- •Header size limit
Unavailable For Legal Reasons
The resource is unavailable due to legal reasons.
Common Use Cases:
- •Content censorship
- •DMCA takedown
- •Geographic restrictions
5xx Server Error
Internal Server Error
The server encountered an unexpected condition that prevented it from fulfilling the request.
Common Use Cases:
- •Unhandled exceptions
- •Server-side bugs
- •Configuration errors
Not Implemented
The server does not support the functionality required to fulfill the request.
Common Use Cases:
- •Unsupported HTTP method
- •Feature not implemented
Bad Gateway
The server, while acting as a gateway, received an invalid response from the upstream server.
Common Use Cases:
- •Proxy server errors
- •Upstream server down
- •Load balancer issues
Service Unavailable
The server is not ready to handle the request, often due to maintenance or overload.
Common Use Cases:
- •Server maintenance
- •Server overload
- •Database connection issues
Gateway Timeout
The server, acting as a gateway, did not receive a timely response from the upstream server.
Common Use Cases:
- •Upstream server timeout
- •Slow backend services
- •Network issues
HTTP Version Not Supported
The server does not support the HTTP protocol version used in the request.
Common Use Cases:
- •Outdated HTTP version
- •Protocol compatibility issues
Variant Also Negotiates
The server has an internal configuration error.
Common Use Cases:
- •Content negotiation misconfiguration
Insufficient Storage
The server is unable to store the representation needed to complete the request.
Common Use Cases:
- •Disk space full
- •Storage quota exceeded
Loop Detected
The server detected an infinite loop while processing the request.
Common Use Cases:
- •WebDAV infinite redirect loops
- •Circular references
Not Extended
Further extensions to the request are required for the server to fulfill it.
Common Use Cases:
- •Extension policy requirements
Network Authentication Required
The client needs to authenticate to gain network access.
Common Use Cases:
- •Captive portal
- •WiFi login required
- •Network access control