What is HTTP 505 Version Not Supported?
The 505 HTTP Version Not Supported response indicates that the server does not support the HTTP protocol version requested by the client.
The server understands HTTP but cannot process the request using that specific version.
Common Causes
- Legacy clients using outdated HTTP versions
- Server restrictions on supported protocols
- Protocol negotiation problems
Example
GET / HTTP/2
If the server only supports HTTP/1.1 it may reject the request with a 505 response.
Why Does It Matter For DevOps?
DevOps engineers may encounter this when managing proxies, load balancers, API gateways, or legacy applications.
Summary
The 505 HTTP Version Not Supported response means the server cannot communicate using the requested HTTP version.