HTTP 308 Permanent Redirect vs 409 Conflict
HTTP 308 (Permanent Redirect) is a 3xx Redirection response, while 409 (Conflict) is a 4xx Client Error response. 308 indicates that the resource has been permanently moved. Like 301, but guarantees the HTTP method will NOT be changed. In contrast, 409 means that the request conflicts with the current state of the server. Often due to concurrent modification or business rule violations.
Description
The resource has been permanently moved. Like 301, but guarantees the HTTP method will NOT be changed.
When You See It
For permanent URL changes where POST requests must remain POST.
How to Fix
Update all references to the new URL. The HTTP method is preserved.
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
308 is a 3xx Redirection response, while 409 is a 4xx Client Error response.
HTTP 308: The resource has been permanently moved. Like 301, but guarantees the HTTP method will NOT be changed.
HTTP 409: The request conflicts with the current state of the server. Often due to concurrent modification or business rule violations.
You encounter 308 when for permanent URL changes where POST requests must remain POST.
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 308 (Permanent Redirect): Update all references to the new URL. The HTTP method is preserved. For 409 (Conflict): Refresh the resource state, resolve conflicts, and retry. Use ETags for optimistic concurrency.