The HTTP417 Expectation Failedclient error response status code indicates that the expectation given in the request'sExpect header could not be met.After receiving a 417 response, a client should repeat the request without anExpect request header, including the file in the request body without waiting for a100 response.See theExpect 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 anExpect: 100-continue header and no request body to avoid sending data over the network that may result in an error such as405,401, or403 response:

PUT /videos HTTP/1.1Host: uploads.example.comContent-Type: video/h264Content-Length: 1234567890987Expect: 100-continue

In this example server implementation, expectations are not supported and the presence of anExpect header with any value results in 417 responses:

HTTP/1.1 417 Expectation FailedDate: Fri, 28 Jun 2024 11:40:58 GMT

The client responds by making a request without expectations and with thecontent in the request body:

PUT /videos HTTP/1.1Host: uploads.example.comContent-Type: video/h264Content-Length: 1234567890987[…]

Specifications

See also

• HTTP response status codes
• 100 Continue
• Expect