HTTP 203 Non-Authoritative Information vs 506 Variant Also Negotiates
HTTP 203 (Non-Authoritative Information) is a 2xx Success response, while 506 (Variant Also Negotiates) is a 5xx Server Error response. 203 indicates that the response payload has been modified by a transforming proxy from the origin server's 200 response. In contrast, 506 means that the server has an internal configuration error: the chosen variant resource is configured to engage in content negotiation itself.
Description
The response payload has been modified by a transforming proxy from the origin server's 200 response.
When You See It
When a proxy or CDN modifies the response body (e.g., adds headers, transforms content).
How to Fix
Check if a proxy is modifying the response. Access the origin directly if you need the original content.
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
203 is a 2xx Success response, while 506 is a 5xx Server Error response.
HTTP 203: The response payload has been modified by a transforming proxy from the origin server's 200 response.
HTTP 506: The server has an internal configuration error: the chosen variant resource is configured to engage in content negotiation itself.
You encounter 203 when when a proxy or CDN modifies the response body (e.g., adds headers, transforms content).
You encounter 506 when rare. Indicates a misconfigured server-side content negotiation loop.
When to Use Which
For 203 (Non-Authoritative Information): Check if a proxy is modifying the response. Access the origin directly if you need the original content. For 506 (Variant Also Negotiates): Fix the server's content negotiation configuration.