| set | 4 | ||||
|---|---|---|---|---|---|
| code | 426 | ||||
| layout | code | ||||
| title | Upgrade Required | ||||
| references |
|
The server refuses to perform the request using the current protocol but might be willing to do so after the client upgrades to a different protocol.
The server MUST send an Upgrade header field in a 426 response to
indicate the required protocol(s)1
Example:
HTTP/1.1 426 Upgrade Required
Upgrade: HTTP/3.0
Connection: Upgrade
Content-Length: 53
Content-Type: text/plain
This service requires use of the HTTP/3.0 protocol.
- 1
UpgradeRFC7230 Section 6.7 - Source: RFC7231 Section 6.5.15