400 HTTP Status Codes
Information about HTTP status codes 400 to 499, their meaning, and any related restrictions.
400 - Client Error
An error situation occurred which seems to be caused by the client. Information about the error should be returned and displayed unless a HEAD request was performed.
The request cannot be processed due to a client error, such as malformed request.
Unused status code originally intended to be used as part of a payment system.
Google Developers API, Shopify, and Stripe use this.
The resource could not be found, but may be available in the future.
The resource is not acceptable according to the accept headers sent by the client.
The client must authenticate with the proxy.
The client did not complete the request within the server's timeout period.
A state conflict prevented the request being processed.
The resource has been removed and is no longer available. No subsequent requests should be made for the resource, and the resource should be removed from any search index.
The client supplied preconditions in the request header and these have not been met by the server.
The request payload is too large.
The requested resource has a media type which the server is unable to support.
The client requested a range which the server is unable to serve. For example, it is beyond the end of the resource.
The client supplied an expect header that the server cannot fulfill.
A hilarious April Fool's joke.
The server is unable to produce a response for the request.
The server does not want to process the request as it might be replayed.
The client should switch to the protocol provided in the upgrade header.
The server requires the request to be conditional so as to prevent an update being lost when a resource is modified.
The resource is rate-limited and the client has sent too many requests in the allotted time.
Some request headers are too large for the server to support.
The server is unable to return the resource due to legal reasons.