4xx Client Error

HTTP 411 Length Required

The server refuses to accept the request without a defined Content-Length header. The client should include the content length when sending a request body.

Common Causes

  • POST/PUT request missing Content-Length header
  • Chunked transfer encoding not supported by server
  • Proxy stripping the Content-Length header

How to Fix

  1. 1Add a Content-Length header to your request
  2. 2Ensure your HTTP client sets Content-Length automatically
  3. 3Check if proxies are modifying request headers

Example

HTTP 411 Length Required
POST /upload HTTP/1.1
(no Content-Length header)

→ 411 Length Required

Related Client Error Codes

400

Bad Request

401

Unauthorized

402

Payment Required

403

Forbidden

404

Not Found

405

Method Not Allowed

406

Not Acceptable

407

Proxy Authentication Required

408

Request Timeout

409

Conflict

410

Gone

412

Precondition Failed

413

Content Too Large

414

URI Too Long

415

Unsupported Media Type

416

Range Not Satisfiable

417

Expectation Failed

418

I'm a Teapot

421

Misdirected Request

422

Unprocessable Content

423

Locked

424

Failed Dependency

425

Too Early

426

Upgrade Required

428

Precondition Required

429

Too Many Requests

431

Request Header Fields Too Large

451

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