index.md

---

title: 417 Expectation Failed
slug: Web/HTTP/Status/417
spec-urls: https://httpwg.org/specs/rfc9110.html#status.417

---

{{HTTPSidebar}}

The HTTP 417 Expectation Failed client error response code indicates that the expectation given in the request's {{HTTPHeader("Expect")}} header could not be met.

See the {{HTTPHeader("Expect")}} header for more details.

Status

417 Expectation Failed

Specifications

{{Specifications}}

See also

• {{HTTPHeader("Expect")}}