The HTTP 417 status code means a server couldn’t understand or doesn’t support the
Before making a request, clients may ask permission from the server to proceed with the request. It’s useful when clients are about to send a large body and do not waste bandwidth in case the server declines their request. This process is facilitated with the help of the
Expect header. This header can only have a single value, which is
Some HTTP clients/libraries append the
Expect header to every request. If you keep getting the
417 Expectation Failed error, try unsetting this header before retrying the request. If you can’t remove this header, you can pass the empty value instead:
Try it yourself
Expect HTTP header with a non-empty value other than
curl -H 'Expect: LOL' -X POST https://example.com
- 100 Continue - status code servers use when they understood the
Expectheader and are ready to proceed with the request.
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