HTTP 411 Length Required

What does HTTP 411 mean?

The server requires a Content-Length header. Some servers refuse request bodies sent with chunked transfer encoding or without a length — common with old proxies and certain upload endpoints.

4xx Client error: The request has a problem the client can fix: wrong URL, missing credentials, bad data or too many requests.

How to fix 411 Length Required

• Send Content-Length with the request body.

411 and SEO

Not relevant for crawling.

Example response

HTTP/1.1 411 Length Required

How to return a 411 response

Node.js (Express)

res.status(411).json({ error: 'Length Required' });

PHP

http_response_code(411);

Python (Flask)

return {'error': 'Length Required'}, 411

Go (net/http)

w.WriteHeader(411)

nginx

return 411;

Related status codes

• 400 Bad Request — The server cannot process the request because it is malformed.
• 413 Content Too Large — The request body is larger than the server allows.

Check which status code a URL returns with the HTTP header checker.