HTTP Status Code Reference

The server cannot process the request due to malformed syntax, invalid parameters, or other client-side errors.

Authentication is required to access the resource. The client must provide valid credentials.

The server understood the request but refuses to authorize it. Authentication will not help.

The requested resource could not be found on the server. This is the most common error encountered on the web.

The HTTP method used is not supported for the requested resource. For example, using POST on a read-only endpoint.

The server timed out waiting for the client to complete the request. The client may retry without modifications.

The request conflicts with the current state of the server, such as editing a resource that was modified by another user.

The resource is no longer available and has been permanently removed. Unlike 404, this indicates intentional removal.

The request payload exceeds the size limit defined by the server. The client should reduce the request size.

The request URI is longer than the server is willing to interpret. This often happens with overly long query strings.

The server refuses the request because the payload format is not supported. Check the Content-Type header.

An April Fools joke from RFC 2324. The server refuses to brew coffee because it is a teapot.

The server understands the content type but cannot process the contained instructions. Often used for validation errors.

The user has sent too many requests in a given amount of time. Used for rate limiting.