HTTP 417 Expectation Failed indicates the server cannot meet the requirements specified in the Expect request header. Currently, the only defined expectation is '100-continue.' A server returns 417 to reject the request before the client sends the body, saving bandwidth. This is the 'rejection' counterpart to 100 Continue — the server is saying 'don't bother sending the body.'
Response includes the status code, standard headers (including Content-Type), and a small diagnostic JSON body describing the request and returned status.
Simulator URL (copy in the app after load — not a normal link):
https://httpstatus.com/api/status/417
Example request:
curl -i "https://httpstatus.com/api/status/417"