Toronto SEO
All HTTP status codes
4xx Client Error
RFC 9110

411 Length Required

The server requires a Content-Length header but the client did not send one.

What it means

HTTP 411 Length Required indicates the server refuses to accept the request without a defined Content-Length header. Common with strict APIs or older HTTP/1.0 servers.

When it's used

Strict server configurations rejecting chunked transfer encoding for POST/PUT.

Common causes
  • Client used Transfer-Encoding: chunked but server requires Content-Length
  • Streaming upload to a server that does not support it
  • Bug in HTTP client library
How to fix it
  • Pre-compute the body and set an explicit Content-Length header
  • Use a server that supports chunked transfer encoding
  • Update your HTTP client library if it incorrectly omits the header
Example response
HTTP/1.1 411 Length Required
Connection: close
SEO impact

Not relevant to crawlers (they always send Content-Length).