421 Misdirected Request (RFC 7540)

This is an educational reference page about HTTP 421 Misdirected Request. The page itself is served as 200 OK so it can be indexed as HTTP documentation.

The request was directed at a server that is not able to produce a response (for example because of connection reuse).

What it means

HTTP 421 Misdirected Request means the request reached a server that cannot produce a response for the target origin.

Common causes

HTTP/2 connection reuse sent a request to a server that is not authoritative for that hostname.
TLS, SNI, reverse-proxy, or virtual-host routing is configured for the wrong origin.
A CDN, gateway, or load balancer routed traffic to a backend that does not serve the requested host.

How to fix it

Check TLS certificates, SNI handling, Host headers, and virtual-host configuration.
Close the reused connection and retry on a connection opened for the correct origin.
Verify CDN and reverse-proxy routing rules for every hostname sharing the same infrastructure.

Example response

HTTP/1.1 421 Misdirected Request
Content-Type: text/plain

Request was directed to a server that cannot handle this origin

Developer notes

421 is most often seen with HTTP/2 and shared infrastructure. Retrying on a fresh connection can be valid, but server routing should still be fixed.

Questions

What does HTTP 421 mean?

HTTP 421 means the server that received the request is not able to respond for the requested origin.

How do I fix 421 Misdirected Request?

Check SNI, Host headers, TLS certificates, virtual hosts, and proxy routing so each hostname reaches the correct backend.