index.md

---

title: 411 Length Required
slug: Web/HTTP/Status/411
spec-urls: https://httpwg.org/specs/rfc9110.html#status.411

---

{{HTTPSidebar}}

The HyperText Transfer Protocol (HTTP) 411 Length Required client error response code indicates that the server refuses to accept the request without a defined {{HTTPHeader("Content-Length")}} header.

Note: by specification, when sending data in a series of chunks, the Content-Length header is omitted and at the beginning of each chunk you need to add the length of the current chunk in hexadecimal format. See {{HTTPHeader("Transfer-Encoding")}} for more details.

Status

411 Length Required

Specifications

{{Specifications}}

See also

• {{HTTPHeader("Content-Length")}}

• {{HTTPHeader("Transfer-Encoding")}}