ErrorFindly
4114xx Client ErrorMedium

HTTP 411 Length Required

Defined in RFC 7231

What Does HTTP 411 Mean?

The server requires the Content-Length header to be defined in the request.

Common Causes

  1. 1Missing Content-Length header on POST/PUT request
  2. 2Chunked transfer encoding not supported by server
  3. 3Proxy requiring Content-Length for request forwarding

Impact

  • ⚠Upload or form submission fails
  • ⚠API request rejected

Developer Fix

For web developers and application engineers

  1. 1Add Content-Length header to requests with bodies
  2. 2Calculate and include content length before sending
  3. 3Avoid chunked encoding if server doesn't support it

Server Admin Fix

For system administrators and DevOps engineers

  1. 1Configure server to accept chunked transfer encoding
  2. 2Update proxy to handle requests without Content-Length
  3. 3Review server requirements for request headers

Frequently Asked Questions

Why does the server need Content-Length?
Some servers need to know the request size upfront for resource allocation, security limits, or because they don't support chunked transfer encoding.
How do I fix an 411 error?
Ensure your HTTP client includes the Content-Length header. Most HTTP libraries do this automatically, but streaming or chunked requests may omit it.

Related HTTP Status Codes

400Bad Request413Payload Too Large

About the Author

Web Infrastructure Team

Verified against official RFC specifications and real-world server configurations. HTTP status code behavior confirmed across Apache, Nginx, and Cloudflare.