HTTP 505 HTTP Version Not Supported vs 506 Variant Also Negotiates
Both HTTP 505 (HTTP Version Not Supported) and 506 (Variant Also Negotiates) belong to the 5xx Server Error category. 505 indicates that the server does not support the HTTP version used in the request. Meanwhile, 506 means that the server has an internal configuration error: the chosen variant resource is configured to engage in content negotiation itself.
Description
The server does not support the HTTP version used in the request.
When You See It
When a client uses an HTTP version the server doesn't support.
How to Fix
Use a supported HTTP version (typically HTTP/1.1 or HTTP/2).
Description
The server has an internal configuration error: the chosen variant resource is configured to engage in content negotiation itself.
When You See It
Rare. Indicates a misconfigured server-side content negotiation loop.
How to Fix
Fix the server's content negotiation configuration.
Key Differences
HTTP 505: The server does not support the HTTP version used in the request.
HTTP 506: The server has an internal configuration error: the chosen variant resource is configured to engage in content negotiation itself.
You encounter 505 when when a client uses an HTTP version the server doesn't support.
You encounter 506 when rare. Indicates a misconfigured server-side content negotiation loop.
When to Use Which
For 505 (HTTP Version Not Supported): Use a supported HTTP version (typically HTTP/1.1 or HTTP/2). For 506 (Variant Also Negotiates): Fix the server's content negotiation configuration.