4xx Client Error

HTTP 421 Misdirected Request

The request was directed at a server that is not able to produce a response. This can happen when a server is not configured for the combination of scheme and authority included in the request URI.

Common Causes

  • HTTP/2 connection coalescing to the wrong server
  • TLS certificate doesn't match the requested hostname
  • Server not configured for the requested domain

How to Fix

  1. 1Verify the server's TLS certificate covers the requested domain
  2. 2Ensure DNS is pointing to the correct server
  3. 3Check HTTP/2 connection reuse settings

Example

HTTP 421 Misdirected Request
GET https://other-domain.com/page HTTP/2
(sent over reused connection to wrong server)

→ 421 Misdirected Request

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

411

Length Required

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

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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