411 Length Required
4xx Client Error
RFC 9110
Send a Content-Length header — the server won't guess.
What 411 Length Required means {#what}
The server refuses to process the request because it requires a Content-Length header that wasn’t provided. Mostly relevant for older server configurations; modern HTTP clients usually send it automatically.
When you’ll see a 411 {#when}
- Custom HTTP clients or scripts that don’t set
Content-Length - Some strict server configurations