This interim response indicates that the client should continue the request or ignore the response if the request is already finished.

Tip: Used when a request is large and the client is waiting for confirmation to continue.

This code is sent in response to an Upgrade request header from the client and indicates the protocol the server is switching to.

Tip: Used to switch protocols like HTTP to WebSocket when requested by the client.

This code was used in WebDAV contexts to indicate that a request has been received by the server, but no status was available at the time of the response.

Tip: Rarely used. Indicates that processing is ongoing, especially for WebDAV operations.

This status code is primarily intended to be used with the Link header, letting the user agent start preloading resources while the server prepares a response.

Tip: Helps browsers preload resources before full response is ready.

The request succeeded. The result depends on the HTTP method (GET, POST, PUT, etc.).

Tip: The most common status. Everything worked as expected.

The request succeeded, and a new resource was created as a result.

Tip: Indicates successful creation. Usually follows a POST request.

The request has been received but not yet acted upon. It may be processed asynchronously.

Tip: Used when processing happens asynchronously or by another service.

Returned metadata may not be from the origin server but a local or third-party copy.

Tip: Content is returned from a third-party cache or mirror.

The server successfully processed the request, but there is no content to send in the response.

Tip: Useful for DELETE requests. No body returned but operation succeeded.

Tells the user agent to reset the document which sent this request.

Tip: Used in UIs to signal the client to reset the form or page state.

Used when the server is delivering only part of the resource due to a range header sent by the client.

Tip: Common in video streaming and range-based downloads.

Used in WebDAV to convey status for multiple independent operations.

Tip: Provides status for multiple related operations, used in WebDAV.

Used inside WebDAV <propstat> elements to avoid repeating information about internal bindings.

Tip: Avoids duplication in WebDAV multi-binding responses.

Server fulfilled a GET request with a response that represents the result of instance manipulations.

Tip: Used when the response contains transformed content (e.g., delta encoding).

The request has more than one possible response. User or user agent should select one of them.

Tip: The client should choose one of the available options. Rarely used in practice.

The URL of the requested resource has been permanently changed.

Tip: Use the new URL in future requests. Search engines update their links to the new one.

The requested resource resides temporarily under a different URI.

Tip: Temporary redirect. Use original URI for future requests.

The response to the request can be found under another URI using a GET method.

Tip: Redirect using GET. Common after form submission or actions.

Indicates that the resource has not been modified since the last request.

Tip: Used for caching. Saves bandwidth by reusing local cache.

Defined in a previous specification to indicate that a requested response must be accessed by a proxy. Deprecated due to security concerns.

Tip: Deprecated. Avoid using this code in new applications.

This response code is no longer used, but is reserved.

Tip: Reserved for future use. Not actively used today.

Redirects to a different URI, but must use the same HTTP method as the original request.

Tip: Same method is retained (e.g., POST stays POST) in redirection.

Similar to 301, but the method and body are preserved across the redirect.

Tip: Use when both the URL and method should be preserved permanently.

The server cannot or will not process the request due to client error.

Tip: Check request syntax and parameters. Ensure all required fields are provided.

Client must authenticate to get the requested response. "Unauthorized" means unauthenticated.

Tip: Provide valid authentication credentials.

Reserved for digital payment systems; rarely used.

Tip: Implement payment workflow if needed.

Client authenticated but does not have access rights to the content.

Tip: Check user permissions and roles.

Requested resource could not be found on the server.

Tip: Verify the URL or resource existence.

Request method is not supported by the target resource.

Tip: Use allowed HTTP methods only.

Server cannot produce a response matching the list of acceptable values sent by the client.

Tip: Check Accept headers for supported content types.

Client must authenticate itself with the proxy.

Tip: Authenticate with proxy server.

Server timed out waiting for the request.

Tip: Retry the request after ensuring connectivity.

Request conflicts with the current state of the server.

Tip: Resolve conflicts before retrying.

Requested resource is permanently deleted and no forwarding address is known.

Tip: Remove cached links to the resource.

Request rejected because Content-Length header is missing.

Tip: Include Content-Length header in request.

Precondition given in request headers evaluated to false by server.

Tip: Verify preconditions before sending request.

Request entity is larger than limits defined by server.

Tip: Reduce the size of the request payload.

The URI requested is longer than the server is willing to interpret.

Tip: Use shorter URIs or POST data for large queries.

The media format of the requested data is not supported by the server.

Tip: Check Content-Type header and use supported media types.

The range specified in the request cannot be fulfilled.

Tip: Verify Range headers are valid.

The expectation given in the Expect request header could not be met by the server.

Tip: Adjust or remove Expect header.

The server refuses to brew coffee with a teapot.

Tip: Easter egg status code.

Request directed at a server that is not able to produce a response.

Tip: Verify target server.

Request well-formed but semantic errors prevent processing (WebDAV).

Tip: Fix semantic errors in request payload.

Resource is locked (WebDAV).

Tip: Retry after lock is released.

Request failed due to failure of a previous request (WebDAV).

Tip: Resolve previous errors first.

Server is unwilling to risk processing a request that might be replayed.

Tip: Retry later to avoid replay issues.

Client should switch to a different protocol as requested by server.

Tip: Upgrade client protocol as indicated.

Origin server requires request to be conditional to prevent lost updates.

Tip: Add required precondition headers.

User sent too many requests in a given time (rate limiting).

Tip: Slow down request rate or wait to retry.

Server refuses to process request because headers are too large.

Tip: Reduce header size and retry.

Resource is unavailable due to legal reasons like censorship.

Tip: Check legal access restrictions.

The server has encountered a situation it does not know how to handle. This error is generic, indicating that the server cannot find a more appropriate 5XX status code to respond with.

Tip: Generic server error. Often indicates a bug or unexpected condition on the server.

The request method is not supported by the server and cannot be handled. The only methods that servers are required to support (and therefore that must not return this code) are GET and HEAD.

Tip: Indicates the server does not support the functionality required to fulfill the request.

This error response means that the server, while working as a gateway to get a response needed to handle the request, got an invalid response.

Tip: Common in setups where a proxy or gateway fails to receive a valid response from an upstream server.

The server is temporarily unavailable, often due to maintenance or overload. A user-friendly message should accompany this response. The Retry-After header indicates when the service will be available again. Caching should generally be disabled for this response.

Tip: Use Retry-After header to tell clients when to try again.

This error response is given when the server is acting as a gateway and cannot get a response in time.

Tip: Timeout between a proxy or gateway and an upstream server.

The HTTP version used in the request is not supported by the server.

Tip: Server refuses to support the HTTP protocol version used in the request.

The server has an internal configuration error: during content negotiation, the chosen variant is configured to engage in content negotiation itself, causing circular references.

Tip: Rare error caused by server misconfiguration during content negotiation.

The method could not be performed on the resource because the server is unable to store the representation needed to successfully complete the request.

Tip: Occurs when server storage limits are exceeded.

The server detected an infinite loop while processing the request.

Tip: Indicates infinite processing loops detected by the server.

The client request declares an HTTP Extension that should be used to process the request, but the extension is not supported by the server.

Tip: Used when the server refuses unsupported HTTP extensions.

Indicates that the client needs to authenticate to gain network access.

Tip: Requires network-level authentication before accessing resources.