406 Not Acceptable
4xx Client Error

The 406 (Not Acceptable) status code indicates that the target resource does not have a current representation that would be acceptable to the user agent, according to the proactive negotiation header fields received in the request, and the server is unwilling to supply a default representation.

The server SHOULD generate a payload containing a list of available representation characteristics and corresponding resource identifiers from which the user or user agent can choose the one most appropriate.

RFC 7231 6.5.6


There’s a set of headers that a client can send to define how it wants the resource it’s requesting:

In a scenario where the client sends those headers but the server can’t serve up a thing that matches, 406 Not Acceptable is an acceptable response…