417 Expectation Failed
The HTTP 417 Expectation Failed client error response status code indicates that the expectation given in the request's Expect header could not be met.
After receiving a 417 response, a client should repeat the request without an Expect request header, including the file as a payload in the request body without waiting for a 100 response.
See the Expect header documentation for more details.
Status
417 Expectation Failed
Examples
Expectations unsupported
The following PUT request sends information about an intended file upload to a server.
The client uses an Expect: 100-continue header and no request body to avoid sending data over the network that may result in an error such as 405, 401, or 403 response:
PUT /videos HTTP/1.1
Host: uploads.example.com
Content-Type: video/h264
Content-Length: 1234567890987
Expect: 100-continue
In this example server implementation, expectations are not supported and the presence of an Expect header with any value results in 417 responses:
HTTP/1.1 417 Expectation Failed
Date: Fri, 28 Jun 2024 11:40:58 GMT
The client responds by making a request without expectations and with the payload in the request body:
PUT /videos HTTP/1.1
Host: uploads.example.com
Content-Type: video/h264
Content-Length: 1234567890987
[…]
Specifications
| Specification |
|---|
| HTTP Semantics # status.417 |