All HTTP status codes

HTTP 417 Expectation Failed

Client Error

The server can't meet the requirements of the Expect header (almost always Expect: 100-continue).

Defined in RFC 9110

Common causes

  • Proxies or old servers that don't support 100-continue

How to fix it

  1. Retry without the Expect header (e.g. curl: -H 'Expect:')

Related status codes

100 Continue

The server received the request headers and the client should proceed to send the request body. Used with the Expect: 100-continue header on large uploads.

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