HTTP 407 Proxy Authentication Required vs 409 Conflict
Both HTTP 407 (Proxy Authentication Required) and 409 (Conflict) belong to the 4xx Client Error category. 407 indicates that the client must first authenticate itself with the proxy. Meanwhile, 409 means that the request conflicts with the current state of the server. Often due to concurrent modification or business rule violations.
Description
The client must first authenticate itself with the proxy.
When You See It
When accessing the internet through a corporate proxy that requires authentication.
How to Fix
Configure proxy credentials in your HTTP client or browser settings.
Description
The request conflicts with the current state of the server. Often due to concurrent modification or business rule violations.
When You See It
When trying to create a resource that already exists, or updating a resource that was modified by another request.
How to Fix
Refresh the resource state, resolve conflicts, and retry. Use ETags for optimistic concurrency.
Key Differences
HTTP 407: The client must first authenticate itself with the proxy.
HTTP 409: The request conflicts with the current state of the server. Often due to concurrent modification or business rule violations.
You encounter 407 when when accessing the internet through a corporate proxy that requires authentication.
You encounter 409 when when trying to create a resource that already exists, or updating a resource that was modified by another request.
When to Use Which
For 407 (Proxy Authentication Required): Configure proxy credentials in your HTTP client or browser settings. For 409 (Conflict): Refresh the resource state, resolve conflicts, and retry. Use ETags for optimistic concurrency.