421
Misdirected Request
4xx Client error
Class
RFC 9110 §15.5.20
Defined in
What does HTTP 421 mean?
The request was sent to a server that cannot answer for that host name. Seen with HTTP/2 connection reuse: the browser reuses a connection for another domain covered by the same TLS certificate, but the server is not configured for that domain.
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 421 Misdirected Request
- Make sure every host name on a shared certificate is configured on the server, or use separate certificates.
421 and SEO
Can block crawling of affected host names until fixed.
Example response
HTTP/1.1 421 Misdirected RequestRelated status codes
- 400 Bad Request — The server cannot process the request because it is malformed.
- 502 Bad Gateway — A gateway or proxy got an invalid response from the upstream server.
Check which status code a URL returns with the HTTP header checker.
All HTTP status codesSearch the full list of status codes from 100 to 599 with their meanings and SEO impact.
Open the full list Frequently asked questions
What does status code 421 mean?
421 Misdirected Request: The request was sent to a server that cannot answer for that host name.
How do I fix a 421 error?
Make sure every host name on a shared certificate is configured on the server, or use separate certificates.
Does 421 affect SEO?
Can block crawling of affected host names until fixed.