HTTP 403 Forbidden vs 421 Misdirected Request
Both HTTP 403 (Forbidden) and 421 (Misdirected Request) belong to the 4xx Client Error category. 403 indicates that the server understood the request but refuses to authorize it. Unlike 401, authentication will not help — the user simply does not have permission. Meanwhile, 421 means that the request was directed at a server that is unable to produce a response for the combination of scheme and authority in the URI.
Description
The server understood the request but refuses to authorize it. Unlike 401, authentication will not help — the user simply does not have permission.
When You See It
When trying to access a resource you're authenticated for but don't have permission to access.
How to Fix
Check your user role/permissions. Contact the admin to request access.
Description
The request was directed at a server that is unable to produce a response for the combination of scheme and authority in the URI.
When You See It
With HTTP/2 when a connection is reused for a domain the certificate doesn't cover.
How to Fix
Retry the request on a new connection.
Key Differences
HTTP 403: The server understood the request but refuses to authorize it. Unlike 401, authentication will not help — the user simply does not have permission.
HTTP 421: The request was directed at a server that is unable to produce a response for the combination of scheme and authority in the URI.
You encounter 403 when when trying to access a resource you're authenticated for but don't have permission to access.
You encounter 421 when with HTTP/2 when a connection is reused for a domain the certificate doesn't cover.
When to Use Which
For 403 (Forbidden): Check your user role/permissions. Contact the admin to request access. For 421 (Misdirected Request): Retry the request on a new connection.